Semiconductor memory device, semiconductor system including the semiconductor memory device, and method for operating the semiconductor memory device

ABSTRACT

A semiconductor memory device includes a first data input/output unit configured to receive a normal training data, whose data window is scanned based on an edge of a source clock, in response to a training input command, and output a data in a state where an edge of the data window is synchronized with the edge of the source clock in response to a training output command, and a second data input/output unit configured to receive a recovery information training data, whose data window is scanned based on the edge of the source clock, in response to the training input command, and output a data in a state where an edge of a data window is synchronized with the edge of the source clock in response to the training output command.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority of Korean Patent Application No.10-2010-0040971, filed on Apr. 30, 2010, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

Exemplary embodiments of the present invention relate to a semiconductordesigning technology, and more particularly, to a circuit for trainingand correcting phases of a write clock and a write data applied to asemiconductor memory device and a method thereof.

A semiconductor memory device stores data in a system composed of aplurality of semiconductor devices. When a data processing apparatus,such as a memory control unit (MCU), requests data, the semiconductormemory device outputs a data corresponding to an address inputted froman apparatus requesting the data, or stores a data provided by the datarequesting apparatus at a location corresponding to the address.

Meanwhile, when an operation temperature of a semiconductor system isaltered or an operation power is changed while a data is transferredbetween the data processing apparatus and the semiconductor memorydevice, there may be a concern regarding the phase of a datainputted/outputted between the data processing apparatus and thesemiconductor memory device.

To be specific, the data inputted/outputted between the data processingapparatus and the semiconductor memory device is inputted/outputted insynchronization with a clock for transferring the data. When theoperation temperature of the semiconductor system is altered or anoperation power is changed while the data is inputted/outputted betweenthe data processing apparatus and the semiconductor memory device, thephase of the data inputted/outputted between the data processingapparatus and the semiconductor memory device and the phase of a clockfor transferring the data may differ, and thus, a data having adifferent phase from the phase of the data at a moment when the databegins being transferred may be outputted. As a result, the datainputted/outputted between the data processing apparatus and thesemiconductor memory device may be recognized in a state of beingshifted backward or forward by one space from an intended state, whichmay raise concern. In other words, the data may not be transferrednormally.

For example, a process where a data is transferred from the dataprocessing apparatus to the semiconductor memory device will bedescribed. Although a data begins to be transferred to the semiconductormemory device in synchronization with the center of a clock fortransferring the data from the data processing apparatus, if theoperation temperature of the semiconductor system is altered or theoperation power is changed, the phase of the data may be changed to bedifferent from the phase of the clock for transferring the data duringthe data transferring process. Therefore, the data received by thesemiconductor memory device is not synchronized with the center of theclock for transferring the data and may be of a state shifted a littlebit to the right/left, and thus the data inputted/outputted between thedata processing apparatus and the semiconductor memory device may berecognized in a state shifted backward or forward by one space from anintended state, which may raise concern.

The above-described concern may become more serious as the transmissionfrequency of the data inputted/outputted between the data processingapparatus and the semiconductor memory device increases. This is becauseas the transmission frequency of the data inputted/outputted between thedata processing apparatus and the semiconductor memory device increases,the length of a data window of the transferred data decreases.Therefore, when the operation temperature of the semiconductor system isaltered or the operation power is changed, the data inputted/outputtedbetween the data processing apparatus and the semiconductor memorydevice may be recognized in a state of being shifted backward or forwardby one space from an intended state.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention are directed to a circuitthat may input/output a data stably all the time between a semiconductormemory device controller and a semiconductor memory device, regardlessof whether the phase of the data is changed due to a change in theoperation temperature or operation power of a semiconductor system whenthe data is inputted/outputted between the semiconductor memory devicecontroller and the semiconductor memory device.

In accordance with an exemplary embodiment of the present invention, asemiconductor memory device includes a first data input/output unitconfigured to receive a normal training data, whose data window isscanned based on an edge of a source clock, in response to a traininginput command, and output a data in a state where an edge of the datawindow is synchronized with the edge of the source clock in response toa training output command, and a second data input/output unitconfigured to receive a recovery information training data, whose datawindow is scanned based on the edge of the source clock, in response tothe training input command, and output a data in a state where an edgeof a data window is synchronized with the edge of the source clock inresponse to the training output command.

The first data input/output unit may receive a normal data in a statewhere a center of a data window is synchronized with the edge of thesource clock in response to a write command, and output a data in astate where an edge of the data window is synchronized with the edge ofthe source clock in response to a read command. The second datainput/output unit may receive a recovery information data whose edge ofa data window is synchronized with the edge of the source clock inresponse to a predetermined command, which is not the training inputcommand or the training output command, and output a data whose edge ofa data window is synchronized with the edge of the source clock after apredetermined time.

In accordance with another exemplary embodiment of the presentinvention, a semiconductor system including a semiconductor memorydevice and a semiconductor memory device controller between which anormal data and a recovery information data are transferred includes thesemiconductor memory device controller configured to compare a recoveryinformation training data with a feedback recovery information trainingdata to produce a comparison result, and control a phase of the recoveryinformation data transferred to the semiconductor memory device based onthe comparison result, and the semiconductor memory device configured toreceive the recovery information training data from the semiconductormemory device controller at a predetermined first moment and transferthe feedback recovery information training data to the semiconductormemory device controller at a predetermined second moment.

The semiconductor memory device controller may compare a normal trainingdata with a feedback normal training data to produce a comparisonresult, and may control a phase of the normal data transferred to thesemiconductor memory device based on the comparison result. Thesemiconductor memory device may receive the normal training data fromthe semiconductor memory device controller at the first moment, and maytransfer the feedback normal training data at the second moment. Thesemiconductor memory device controller may compare the recoveryinformation data with the feedback recovery information data to producea comparison result, and controls a phase of the normal data transferredto the semiconductor memory device based on the comparison result. Thesemiconductor memory device may receive the recovery information datafrom the semiconductor memory device controller at the first moment, andmay transfer the feedback recovery information data to the semiconductormemory device controller after a predetermined time.

In accordance with yet another exemplary embodiment of the presentinvention, a semiconductor system includes a semiconductor memory devicecontroller configured to control a phase of a recovery information datatransferred to the semiconductor memory device in a normal mode inresponse to a feedback recovery information training data transferredfrom the semiconductor memory device based on a recovery informationtraining data transferred to the semiconductor memory device in atraining mode, and a semiconductor memory device configured to store therecovery information training data transferred from the semiconductormemory device controller in the training mode for a first time periodand feed-back the stored recovery information training data as thefeedback recovery information training data, and to store the recoveryinformation data transferred from the semiconductor memory devicecontroller in the normal mode for a second time period and feed-back thestored recovery information data as the feedback recovery informationdata.

In accordance with still another exemplary embodiment of the presentinvention, a method for operating a semiconductor memory device includesapplying a training input command, applying a normal training data and arecovery information training data at a first moment, after the applyingof the training input command, by scanning each data window based on anedge of a source clock, applying a training output command, outputtingthe received normal training data and the received recovery informationtraining data at a second moment in a state where an edge of a datawindow is synchronized with the edge of the source clock, after theapplying of the training output command.

The method may further include applying a write command, applying a readcommand, applying a first normal data at the first moment after theapplying of the write command in a state where a center of a data windowis synchronized with the edge of the source clock, and outputting asecond normal data stored inside at the second moment after the applyingof the read command in a state where an edge of a data window issynchronized with the edge of the source clock. The method may furtherinclude applying a predetermined command, and receiving a recoveryinformation data in a state where an edge of a data window issynchronized with the edge of the source clock at the first moment,after the applying of the write command, the read command, and thepredetermined command, and outputting the applied data in a state whereedges of data windows are synchronized with the edge of the source clockafter a predetermined time.

In accordance with still another exemplary embodiment of the presentinvention, a method for operating a semiconductor system including asemiconductor memory device and a semiconductor memory device controllerincludes transferring a training input command generated in thesemiconductor memory device controller to the semiconductor memorydevice and transferring a recovery information training data generatedin the semiconductor memory device controller to the semiconductormemory device at a first time by scanning a data window based on an edgeof a source clock, storing the recovery information training datatransferred to the semiconductor memory device inside the semiconductormemory device, transferring a training output command generated in thesemiconductor memory device controller to the semiconductor memorydevice and outputting the stored recovery information training data as afeedback recovery information training data to the semiconductor memorydevice controller at a second time in a state that an edge of a datawindow is synchronized with the edge of the source clock, and comparinga data value of the feedback recovery information training dataoutputted to the semiconductor memory device controller with therecovery information training data inside the semiconductor memorydevice controller to produce a comparison result, and controlling aphase of a recovery information data generated in the semiconductormemory device controller and transferred to the semiconductor memorydevice based on the comparison result.

The method may further include transferring a write command generated inthe semiconductor memory device controller to the semiconductor memorydevice and transferring a first normal data generated in thesemiconductor memory device controller to the semiconductor memorydevice at the first time in a state where a center of a data window issynchronized with the edge of the source clock, and transferring a readcommand generated in the semiconductor memory device controller to thesemiconductor memory device and transferring a second normal data storedinside the semiconductor memory device to the semiconductor memorydevice controller after the second time in a state where an edge of adata window is synchronized with the edge of the source clock.

The method may further include transferring a predetermined commandgenerated in the semiconductor memory device controller, including thewrite command and the read command and excluding the training inputcommand and the training output command to the semiconductor memorydevice, and transferring the recovery information data generated in thesemiconductor memory device controller to the semiconductor memorydevice after the first time in a state where an edge of a data window issynchronized with the edge of the source clock, storing the recoveryinformation data transferred to the semiconductor memory device insidethe semiconductor memory device, transferring the recovery informationdata stored in the semiconductor memory device as a feedback recoveryinformation data to the semiconductor memory device controller in astate where an edge of a data window is synchronized with the edge ofthe source clock, after the storing of the recovery information data iscompleted and a predetermined time elapses, and comparing a data valueof the feedback recovery information data transferred to thesemiconductor memory device controller with the recovery informationdata inside the semiconductor memory device controller to produce acomparison result, and controlling a phase of the first normal databased on the comparison result.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are block diagrams illustrating a semiconductor memorydevice in accordance with an exemplary embodiment of the presentinvention.

FIG. 2A is a circuit diagram illustrating a training input commandsensor of the semiconductor memory device shown in FIGS. 1A and 1B.

FIG. 2B is a circuit diagram illustrating a training output commandsensor of the semiconductor memory device shown in FIGS. 1A and 1B.

FIG. 3A is a circuit diagram illustrating a recovery information (WCDR)input counter of the semiconductor memory device shown in FIGS. 1A and1B.

FIG. 3B is a circuit diagram illustrating a NAND flip flop of therecovery information input counter shown in FIG. 2.

FIG. 4 is a circuit diagram illustrating a recovery information inputlatch signal toggling unit of the semiconductor memory device shown inFIGS. 1A and 1B.

FIG. 5 is a circuit diagram illustrating first and second recoveryinformation output enable signal toggling controllers of thesemiconductor memory device shown in FIGS. 1A and 1B.

FIG. 6A is a circuit diagram illustrating an internal input strobesignal toggling unit of the semiconductor memory device shown in FIGS.1A and 1B.

FIG. 6B is a circuit diagram illustrating a plurality of serial flipflops of the internal input strobe signal toggling unit shown in FIG.6A.

FIG. 6C is a circuit diagram illustrating a feedback flip flop of theinternal input strobe signal toggling unit shown in FIG. 6A.

FIG. 7A is a circuit diagram illustrating an internal output strobesignal toggling unit of the semiconductor memory device shown in FIGS.1A and 1B.

FIG. 7B is a circuit diagram illustrating each of a plurality ofinternal output strobe signal generators shown in FIG. 7A.

FIG. 7C is a circuit diagram illustrating each of a plurality of serialflip flops of the internal output strobe signal toggling unit shown inFIG. 7A.

FIG. 7D is a circuit diagram illustrating one feedback flip flop of theinternal output strobe signal toggling unit shown in FIG. 7A.

FIG. 8A is a circuit diagram illustrating a recovery information outputdriver enable signal toggling unit of the semiconductor memory deviceshown in FIGS. 1A and 1B.

FIG. 8B is circuit diagram illustrating a plurality of serial flip flopsof the recovery information output driver enable signal toggling unitshown in FIG. 1A.

FIG. 9 is a block diagram illustrating a semiconductor system includingthe semiconductor memory device shown in FIGS. 1A and 1B.

FIG. 10 is a timing diagram illustrating an operation of applying atraining input command to a semiconductor memory device in accordancewith an exemplary embodiment of the present invention.

FIG. 11 is a timing diagram illustrating an operation of applying atraining output command to a semiconductor memory device in accordancewith an exemplary embodiment of the present invention.

FIG. 12 illustrates an operation of applying a data in the state of adata window being scanned based on the edge of a source clock inaccordance with an exemplary embodiment of the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Exemplary embodiments of the present invention will be described belowin more detail with reference to the accompanying drawings. The presentinvention may, however, be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the present invention tothose skilled in the art. Throughout the disclosure, like referencenumerals refer to like parts throughout the various figures andembodiments of the present invention.

The drawings are not necessarily to scale and in some instances,proportions may have been exaggerated in order to clearly illustratefeatures of the embodiments. When a first layer is referred to as being“on” a second layer or “on” a substrate, it not only refers to a casewhere the first layer is formed directly on the second layer or thesubstrate, but also a case where a third layer exists between the firstlayer and the second layer or the substrate.

FIGS. 1A and 1B are block diagrams illustrating a semiconductor memorydevice in accordance with an exemplary embodiment of the presentinvention.

Referring to FIGS. 1A and 1B, the semiconductor memory device accordingto an exemplary embodiment of the present invention includes a firstdata input/output unit 100 and a second data input/output unit 120. Thefirst data input/output unit 100 receives a normal training data NORMALTRAIN DATA, whose data window is scanned based on an edge of a sourceclock ISCK, in response to a training input command IWRTR, and outputs adata FB NORMAL TRAIN DATA in a state where an edge of the data window issynchronized with an edge of the source clock ISCK in response to atraining output command IRDTR. The second data input/output unit 120receives a recovery information training data WCDR TRAIN DATA in a statewhere a data window is scanned based on the edge of the source clockISCK in response to a training input command IWRTR, and outputs a dataFB WCDR TRAIN DATA in a state where an edge of the data window issynchronized with the edge of the source clock ISCK in response to thetraining output command IRDTR.

Herein, the first data input/output unit 100 includes a block 104, whichreceives a normal data NORMAL DATA, whose center of a data window issynchronized with the edge of the source clock ISCK, in response to awrite command IWT, and outputs a data NORMAL DATA in a state where theedge of the data window is synchronized with the edge of the sourceclock ISCK in response to a read command IRD along with a block 102,which receives a normal training data NORMAL TRAIN DATA, whose datawindow is scanned based on an edge of a source clock ISCK, in responseto a training input command IWRTR, and outputs a data FB NORMAL TRAINDATA in a state where the edge of the data window is synchronized withthe edge of the source clock ISCK in response to a training outputcommand IRDTR.

The second data input/output unit 120 includes a structure whichreceives a recovery information data WCDR DATA whose edge of a datawindow is synchronized with the edge of the source clock ISCK inresponse to a predetermined command IWCDR, which is not the traininginput command IWRTR or the training output command IRDTR, and outputs adata FB WCDR DATA whose edge of a data window is synchronized with theedge of the source clock ISCK after a certain time.

The semiconductor memory device according to the exemplary embodiment ofthe present invention further includes a command input pad 182, a normaldata input/output pad 181, a recovery information (WCDR) datainput/output pad 185, and clock input pads 183 and 184. The commandinput pad 182 receives a training input command IWRTR, a training outputcommand IRDTR, and a predetermined command IWCDR. The normal datainput/output pad 181 inputs/outputs normal data NORMAL DATA and FBNORMAL DATA and normal training data NORMAL TRAIN DATA and FB NORMALTRAIN DATA. The WCDR data input/output pad 185 inputs/outputs recoverydata WCDR DATA and FB WCDR DATA and recovery information training dataWCDR DATA and FB WCDR DATA. The clock input pads 183 and 184 receivesource clocks ISCK(IHCK) and ISCK(IWCK).

Herein, the second data input/output unit 120 performs an operation ofreceiving and outputting a recovery information data WCDR DATA or arecovery information training data WCDR TRAIN DATA, when thesemiconductor memory device enters a recovery information operation modeor a recovery information training operation mode.

Herein, entering the recovery information operation mode or a recoveryinformation training operation mode signifies that a recoveryinformation enable signal WCDR_ENABLE is enabled/disabled.

Also, the enable moment and disable moment of the recovery informationenable signal WCDR_ENABLE and the length of an enabled duration arepredetermined in a memory register setting (MRS) 140.

The predetermined command IWCDR includes a write command IWT and a readcommand IRD. Also, the predetermined command IWCDR may further includediverse operation mode commands for a semiconductor memory device, otherthan the write command IWT and the read command IRD. In particular, apredetermined command IWCDR may include an auto-refresh operation modeentering command, which is one of the operation modes that uses the mostpower in a semiconductor memory device, or conversely include a stand-byoperation mode entering command, which is one of the operation modesthat uses the least power in a semiconductor memory device.

The reason why the predetermined command IWCDR can include the writecommand IWT, the read command IRD, and other diverse operation modecommands for a semiconductor memory device is that a command decoder 160is designed to toggle the predetermined command IWCDR when the writecommand IWT, the read command IRD, and other diverse operation modecommands for a semiconductor memory device are toggled in a case wherethe recovery information enable signal WCDR_ENABLE is enabled and thesemiconductor memory device enters the recovery information operationmode or the recovery information training operation mode.

Also, the time elapsing from a moment when the training input commandIWRTR is inputted into the command input pad 182 to a moment when thenormal training data NORMAL TRAIN DATA is inputted into the normal datainput/output pad 181 is the same as the time elapsing from a moment whenthe training input command IWRTR is inputted into the command input pad182 to a moment when the recovery information training data WCDR TRAINDATA is inputted into the recovery information data input/output pad185.

Also, because the time elapsing from a moment when the training outputcommand IRDTR is inputted into the command input pad 182 to a momentwhen the normal training data FB NORMAL TRAIN DATA is outputted throughthe normal data input/output pad 181 and the time elapsing from a momentwhen the training output command IRDTR is inputted into the commandinput pad 182 to a moment when the recovery information training data FBWCDR TRAIN DATA is outputted through the recovery information datainput/output pad 185 are determined based on a write latency WL, whichis a value set up in the memory register setting (MRS) 140 of thesemiconductor memory device, the two are the same.

Likewise, the time elapsing from a moment when the write command IWT isinputted into the command input pad 182 to a moment when a normal dataNORMAL DATA is inputted into the normal data input/output pad 181; thetime elapsing from a moment when the predetermined command IWCDR isinputted into the command input pad 182 to a moment when the recoveryinformation data WCDR DATA is inputted into the recovery informationdata input/output pad 185; the time elapsing from a moment when thetraining input command IWRTR is inputted into the command input pad 182to a moment when the normal training data NORMAL TRAIN DATA is inputtedinto the normal data input/output pad 181; and the time elapsing from amoment when the training input command IWRTR is inputted into thecommand input pad 182 to a moment when the recovery information trainingdata WCDR TRAIN DATA is inputted into the recovery information datainput/output pad 185 are determined based on the write latency WL, whichis a value set up in the memory register setting (MRS) 140 of thesemiconductor memory device. Thus, they are the same.

Also, the time elapsing from a moment when the read command IRD isinputted into the command input pad 182 to a moment when the normal dataNORMAL DATA is outputted through the normal data input/output pad 181;and the time elapsing from a moment when the training output commandIRDTR is inputted into the command input pad 182 to a moment when thenormal training data NORMAL TRAIN DATA and the recovery informationtraining data WCDR TRAIN DATA are outputted through the normal datainput/output pad 181 and the recovery information data input/output pad185 are also determined based on a column latency CL, which is a valueset up in the memory register setting (MRS) 140 of the semiconductormemory device. Thus, they are the same. On the other hand, the timeelapsing from a moment when the predetermined command IWCDR is inputtedinto the command input pad 182 to a moment when the recovery informationdata WCDR DATA is outputted through the recovery information datainput/output pad 185 is determined based on a recovery informationlatency WCDR, which is a value set up in the memory register setting(MRS) 140 of the semiconductor memory device. Thus, it is not the same.

Herein, the write latency WL and the column latency CL, which are valuesset up in the memory register setting (MRS) 140, may be generalspecifications that are included in semiconductor memory devices. On theother hand, the recovery information latency WCDRL is a valueindependently set up in the memory register setting (MRS) 140 for theexemplary embodiment of the present invention.

The second data input/output unit 120 includes a recovery informationdata input/output controller 122, recovery information data input/outputunits 124 and 125, and a recovery information storage 126. The recoveryinformation input/output controller 122 generates a first internal inputstrobe signal WCDR PIN<0:M> corresponding to an internal input moment ofthe recovery information training data WCDR TRAIN DATA in response tothe training input command IWRTR, and generates a first internal outputstrobe signal WCDR POUT<0:M> corresponding to an internal output momentof the recovery information training data WCDR TRAIN DATA in response tothe training output command IRDTR. The recovery information datainput/output units 124 and 125 input/output recovery informationtraining data WCDR TRAIN DATA and FB WCDR TRAIN DATA through therecovery information data input/output pad 185. The recovery informationstorage 126 stores the recovery information training data WCDR TRAINDATA for a certain time in response to the first internal input strobesignal WCDR PIN<0:M> and the first internal output strobe signal WCDRPOUT<0:M>.

Herein, the recovery information input/output controller 122 may includea constituent element that generates a second internal input strobesignal WCDR PIN<0:N> corresponding to an internal input moment of therecovery information data WCDR DATA and generates a second internaloutput strobe signal WCDR POUT<0:N> corresponding to an internal outputmoment of the recovery information data WCDR DATA in response to thepredetermined command IWCDR.

Also, the recovery information data input/output units 124 and 125include a constituent element that inputs/outputs recovery informationdata WCDR DATA and FB WCDR DATA through the recovery information datainput/output pad 185.

Also, the recovery information storage 126 includes a constituentelement that stores the recovery information data WCDR DATA for apredetermined time in response to the second internal input strobesignal WCDR PIN<0:N> and the second internal output strobe signal WCDRPOUT<0:N>.

Hereafter, the structure of the recovery information input/outputcontroller 122 will be described in detail. The recovery informationinput/output controller 122 includes a recovery information inputcontrol block 1221, 1222, 1223 and 1228 and a recovery informationoutput control block 1224, 1225, 1226 and 1227. The recovery informationinput control block 1221, 1222, 1223 and 1228 toggles the first internalinput strobe signal WCDR PIN<0:M> or the second internal input strobesignal WCDR PIN<0:N> at a moment after a time period, during which theperiod (TCK) of a source clock repeats a first number of times, elapsesfrom a moment when the training input command IWRTR or the predeterminedcommand IWCDR is inputted. The recovery information output control block1224, 1225, 1226 and 1227 toggles the first internal output strobesignal WCDR POUT<0:M> at a moment after a time period, during which theperiod (TCK) of the source clock ISCK repeats a second number of times,elapses from a moment when the training output command IRDTR isinputted, and toggles the second internal output strobe signal WCDRPOUT<0:N> at a moment after a time period, during which the period (TCK)of the source clock ISCK repeats a third number of times, elapses from amoment when the second internal input strobe signal WCDR PIN<0:N> istoggled.

Herein, the recovery information input control block 1221, 1222, 1223and 1228 includes a recovery information input counter 1221 and an inputstrobe signal generation portion 1222 and 1223. The recovery informationinput counter 1221 counts the period of the source clock ISCK until itreaches the first number of times from a moment when the training inputcommand IWRTR or the predetermined command IWCDR is inputted, andtoggles a recovery information input enable signal WCDRINEN in responseto the completion of the counting. The input strobe signal generationportion 1222 and 1223 generates the first internal input strobe signalWCDR PIN<0:M> in response to the toggling of the recovery informationinput enable signal WCDRINEN when the training input command IWRTR isinputted into the command input pad 182, and generates the secondinternal input strobe signal WCDR PIN<0:N> in response to the recoveryinformation input enable signal WCDRINEN when the predetermined commandIWCDR is inputted into the command input pad 182. The recoveryinformation input control block 1221, 1222, 1223 and 1228 furtherincludes a training input command sensor 1228 which enables a traininginput command sense signal WRTR_FLAG in response to an input of thetraining input command IWRTR, and disables the training input commandsense signal WRTR_FLAG in response to an input of the training outputcommand IRDTR.

The recovery information output control block 1224, 1225, 1226 and 1227includes a first recovery information output enable signal togglingcontroller 1224, a second recovery information output enable signaltoggling controller 1224, and an output strobe signal generation portion1225 and 1226. The first recovery information output enable signaltoggling controller 1224 toggles a recovery information output enablesignal WCDROUTEN in response to a normal output enable signal RDEN whichis toggled at a moment after a time period, during which a number ofperiods of the source clock ISCK counted is the second number of times,elapses from an input moment when the training output command IRDTR isinputted into the command input pad 182. The second recovery informationoutput enable signal toggling controller 1224 counts the third number oftimes that the period of the source clock ISCK repeats in response to atoggling of the recovery information input enable signal WCDRINEN whenthe predetermined command IWCDR is inputted into the command input pad182, and toggles the recovery information output enable signal WCDROUTENin response to the completion of the counting. The output strobe signalgeneration portion 1225 and 1226 generates the first internal outputstrobe signal WCDR POUT<0:M> in response to a toggling of the recoveryinformation output enable signal WCDROUTEN, when the training outputcommand IRDTR is inputted into the command input pad 182, and generatesthe second internal output strobe signal WCDR POUT<0:N> in response to atoggling of the recovery information output enable signal WCDROUTEN,when the predetermined command IWCDR is inputted into the command inputpad 182. The recovery information output control block 1224, 1225, 1226and 1227 further includes a training output command sensor 1227, whichenables a write training output command sense signal RDTR_FLAG inresponse to an input of the training output command IRDTR, and disablesthe training output command sense signal RDTR_FLAG in response to aninput of the training input command IWRTR.

Herein, it may be seen that the first internal input strobe signal WCDRPIN<0:M> and the second internal input strobe signal WCDR PIN<0:N> aredifferent from each other in that the number of signals included is Mand N, respectively, and the first internal output strobe signal WCDRPOUT<0:M> and the second internal output strobe signal WCDR POUT<0:N>are different from each other in that the number of signals included isM and N, respectively. The names of the signals are distinguished fromeach other because their toggling timing is different according to anoperation. The operations will be described in more detail later.

Among the constituent elements of the recovery information outputcontrol block 1224, 1225, 1226 and 1227, the first recovery informationoutput enable signal toggling controller 1224 and the second recoveryinformation output enable signal toggling controller 1224 indicate thesame constituent element. This is because the first recovery informationoutput enable signal toggling controller 1224 and the second recoveryinformation output enable signal toggling controller 1224 performdifferent operations according to whether an input signal is enabled ordisabled. The structures will be described in more detail later, too.

The input strobe signal generation portion 1222 and 1223 includes arecovery information input latch signal toggling unit 1222 and aninternal input strobe signal toggling unit 1223. The recoveryinformation input latch signal toggling unit 1222 toggles a recoveryinformation input latch signal WCDR STROBE with a predetermined timedifference in response to a toggling of the recovery information inputenable signal WCDRINEN. The internal input strobe signal toggling unit1223 toggles the first internal input strobe signal WCDR PIN<0:M> inresponse to a toggling of the recovery information input latch signalWCDR STROBE when the training input command IWRTR is inputted, andtoggles the second internal input strobe signal WCDR PIN<0:N> inresponse to a toggling of the recovery information input latch signalWCDR STROBE when the predetermined command IWCDR is inputted.

Herein, regardless of whether the training input command IWRTR isinputted or the predetermined command IWCDR is inputted, if a command isinputted once and the recovery information input enable signal WCDRINENis toggled once and accordingly the recovery information input latchsignal WCDR STROBE is toggled only one time, any one signalpredetermined among a plurality of signals included in the firstinternal input strobe signal WCDR PIN<0:M> (which is a signal WCDRPIN<0> in most cases because the first internal input strobe signal WCDRPIN<0:M> begins to engage in the operation from the least significantbit (LSB)) is toggled; and any one signal predetermined among aplurality of signals included in the second internal input strobe signalWCDR PIN<0:N> (which is a signal WCDR PIN<0> in most cases because thesecond internal input strobe signal WCDR PIN<0:N> begins to engage inthe operation from the least significant bit (LSB)) is toggled.Therefore, when a command is inputted only once as described above, thefirst internal input strobe signal WCDR PIN<0:M> and the second internalinput strobe signal WCDR PIN<0:N> are substantially the same signal.

However, when the training input command IWRTR or the predeterminedcommand IWCDR is consecutively inputted and the recovery informationinput enable signal WCDRINEN is consecutively toggled, the recoveryinformation input latch signal toggling unit 1222 among the constituentelements of the input strobe signal generation portion 1222 and 1223consecutively toggles the recovery information input latch signal WCDRSTROBE in response to the consecutive toggling of the recoveryinformation input enable signal WCDRINEN with a certain time difference.

Likewise, the internal input strobe signal toggling unit 1223 of theinput strobe signal generation portion 1222 and 1223 sequentially istoggles a plurality of signals included in the first internal inputstrobe signal WCDR PIN<0:M> (WCDR PIN<0>→WCDR PIN<1>→WCDR PIN<2>→ . . .→WCDR PIN<M-1>→WCDR PIN<M>) in response to the consecutive input of thetraining input command IWRTR and the consecutive toggling of therecovery information input latch signal WCDR STROBE performedthereafter; and sequentially toggles a plurality of signals included inthe second internal input strobe signal WCDR PIN<0:N> (WCDR PIN<0>→WCDRPIN<1>→WCDR PIN<2>→ . . . →WCDR PIN<N-1>→WCDR PIN<N>) in response to theconsecutive input of the predetermined command IWCDR and the consecutivetoggling of the recovery information input latch signal WCDR STROBEperformed thereafter.

Therefore, in the above-described case where a command is consecutivelyinputted, the first internal input strobe signal WCDR PIN<0:M> and thesecond internal input strobe signal WCDR PIN<0:N> may be substantiallydifferent signals from each other.

The output strobe signal generation portion 1225 and 1226 includes arecovery information output driver enable signal toggling unit 1226 andan internal output strobe signal toggling unit 1225. The recoveryinformation output driver enable signal toggling unit 1226 consecutivelytoggles the recovery information output driver enable signal WCDR DOUTENABLE as many times as a number corresponding to a bit number of therecovery information data WCDR DATA or the recovery information trainingdata WCDR TRAIN DATA in response to a toggling of the recoveryinformation output enable signal WCDROUTEN. The internal output strobesignal toggling unit 1225 toggles the first internal output strobesignal WCDR POUT<0:M> in response to a toggling of the recoveryinformation output enable signal WCDROUTEN when the training outputcommand IRDTR is inputted; and toggles the second internal output strobesignal WCDR POUT<0:N> in response to a toggling of the recoveryinformation output enable signal WCDROUTEN when the predeterminedcommand IWCDR is inputted.

Herein, regardless of whether the training output command IRDTR isinputted or the predetermined command IWCDR is inputted, if a command isinputted once and the recovery information output enable signalWCDROUTEN is toggled once, any one predetermined signal from among aplurality of signals included in the first internal output strobe signalWCDR POUT<0:M> (which is a signal WCDR POUT<0> in most cases because thefirst internal output strobe signal WCDR POUT<0:M> begins to engage inthe operation begins from the least significant bit (LSB)) is toggled;and any one predetermined signal from among a plurality of signalsincluded in the second internal output strobe signal WCDR POUT<0:N>(which is a signal WCDR POUT<0> in most cases because the secondinternal output strobe signal WCDR POUT<0:N> begins to engage in theoperation begins from the least significant bit (LSB)) is toggled.Therefore, when a command is inputted only once as described above, thefirst internal output strobe signal WCDR POUT<0:M> and the secondinternal output strobe signal WCDR POUT<0:N> are substantially the samesignal.

However, when the training output command IRDTR or the predeterminedcommand IWCDR is consecutively inputted and the recovery informationoutput enable signal WCDRINEN is consecutively toggled, the recoveryinformation output driver enable signal toggling unit 1226 of the outputstrobe signal generation portion 1225 and 1226 consecutively toggles therecovery information output driver enable signal WCDR DOUT ENABLE asmany times as a number corresponding to a bit number of the recoveryinformation data WCDR DATA or the recovery information training dataWCDR TRAIN DATA whenever the recovery information output enable signalWCDROUTEN is consecutively toggled.

Likewise, the internal output strobe signal toggling unit 1225 of theoutput strobe signal generation portion 1225 and 1226 sequentiallytoggles a plurality of signals included in the first internal outputstrobe signal WCDR P OUT <0:M> (WCDR POUT <0>→WCDR POUT <1>→WCDR POUT<2>→ . . . →WCDR POUT <M-1>→WCDR POUT <M>) in response to theconsecutive input of training output command IRDTR and the consecutivetoggling of the recovery information output enable signal WCDROUTENperformed thereafter; and sequentially toggles a plurality of signalsincluded in the second internal output strobe signal WCDR POUT <0:N>(WCDR POUT <0>→WCDR POUT <1>→WCDR POUT <2>→ . . . →WCDR POUT <N-1>→WCDRPOUT <N>) in response to the consecutive input of the predeterminedcommand IWCDR and the consecutive toggling of the recovery informationoutput enable signal WCDROUTEN performed thereafter.

Therefore, in the above-described case where a command is consecutivelyinputted, the first internal output strobe signal WCDR POUT <0:M> andthe second internal output strobe signal WCDR POUT <0:N> may besubstantially different signals from each other.

The recovery information data input/output units 124 and 125 include arecovery information data input unit 124 and a recovery information dataoutput unit 125. The recovery information data input unit 124 buffers asignal S_WCDR IN DATA which corresponds to the recovery information dataWCDR DATA or the recovery information training data WCDR TRAIN DATA towhich a plurality of bits are serially applied through the recoveryinformation data input/output pad 185, synchronizes it with the sourceclock ISCK for parallelization, and outputs it as a signal P_WCDR ALIGNDATA. The recovery information data output unit 125 synchronizes asignal P_WCDR OUT DATA, which corresponds to the recovery informationdata WCDR DATA or the recovery information training data WCDR TRAIN DATAprovided in a parallelized state through the recovery informationstorage 126, with the source clock ISCK for serialization, and outputs aserialized signal as a signal S_WCDR OUT DATA; and outputs a feedbackrecovery information data FB WCDR DATA or a feedback recoveryinformation training data FB WCDR TRAIN DATA through the recoveryinformation data input/output pad 185 in response to a toggling of therecovery information output driver enable signal WCDR DOUT ENABLE.

The recovery information data input unit 124 of the recovery informationdata input/output units 124 and 125 includes a recovery information datainput driver 1242 and a recovery information data parallelize unit 1244.

The recovery information data input driver 1242 sequentially buffersrecovery information data WCDR DATA, or recovery information trainingdata WCDR TRAIN DATA, of which a plurality of consecutive bits areserially applied through the recovery information data input/output pad185.

The recovery information data parallelize unit 1244 sequentiallyparallelizes the buffered data in synchronization with the source clockISCK.

Herein, when the training output command IRDTR or the predeterminedcommand IWCDR are consecutively inputted and the recovery informationoutput enable signal WCDROUTEN is consecutively toggled, the recoveryinformation data input unit 124 sequentially buffers signals S_WCDR INDATA0, S_WCDR IN DATA1, . . . , S_WCDR IN DATAM or S_WCDR IN DATA0,S_WCDR IN DATA1, . . . , S_WCDR IN DATAN, which correspond to aplurality of recovery information data WCDR DATA0, WCDR DATA1, . . . ,WCDR DATAM or WCDR DATA0, WCDR DATA1, . . . , WCDR DATAN, or a pluralityof recovery information training data WCDR TRAIN DATA0, WCDR TRAINDATA1, . . . , WCDR TRAIN DATAM or WCDR TRAIN DATA0, WCDR TRAIN DATA1, .. . , WCDR TRAIN DATAN, to which a plurality of consecutive bits areserially applied through the recovery information data input/output pad185; sequentially parallelizes them in synchronization with the sourceclock ISCK; and outputs them as signals P_WCDR ALIGN DATA0, P_WCDR ALIGNDATA1, . . . , P_WCDR ALIGN DATAM or P_WCDR ALIGN DATA0, P_WCDR ALIGNDATA1, . . . , P_WCDR ALIGN DATAN.

Likewise, when the training input command IWRTR or the predeterminedcommand IWCDR are consecutively inputted and the recovery informationoutput enable signal WCDROUTEN is consecutively toggled, the recoveryinformation data output unit 125 sequentially serializes insynchronization with the source clock ISCK signals P_WCDR ALIGN DATA0,P_WCDR ALIGN DATA1, . . . , P_WCDR ALIGN DATAM or P_WCDR ALIGN DATA0,P_WCDR ALIGN DATA1, . . . , P_WCDR ALIGN DATAN, which correspond to aplurality of parallelized recovery information data WCDR DATA0, WCDRDATA1, . . . , WCDR DATAM or WCDR DATA0, WCDR DATA1, . . . , WCDR DATAN,or a plurality of recovery information training data WCDR TRAIN DATA0,WCDR TRAIN DATA1, . . . , WCDR TRAIN DATAM or WCDR TRAIN DATA0, WCDRTRAIN DATA1, . . . , WCDR TRAIN DATAN that are sequentially providedthrough the recovery information storage 126; and outputs them assignals S_WCDR ALIGN DATA0, S_WCDR ALIGN DATA1, . . . , S_WCDR ALIGNDATAM or S_WCDR ALIGN DATA0, S_WCDR ALIGN DATA1, . . . , S_WCDR ALIGNDATAN; and in response to the recovery information output driver enablesignal WCDR DOUT ENABLE, outputs them as a plurality of feedbackrecovery information data FB WCDR DATA0, FB WCDR DATA1, . . . , FB WCDRDATAM or FB WCDR DATA0, FB WCDR DATA1, . . . , FB WCDR DATAN, or aplurality of feedback recovery information training data FB WCDR TRAINDATA0, FB WCDR TRAIN DATA1, . . . , FB WCDR TRAIN DATAM or FB WCDR TRAINDATA0, FB WCDR TRAIN DATA1, . . . , FB WCDR TRAIN DATAN.

Further, the recovery information storage 126 includes a recoveryinformation latch unit 1262 and a recovery information data storage unit1264<0:M> or 1264<0:N>. The recovery information latch unit 1262 latchesa signal P_WCDR ALIGN DATA corresponding to the recovery informationdata WCDR DATA or the recovery information training data WCDR TRAINDATA, which is parallelized through the recovery information data inputunit 124, in parallel in response to a toggling of the recoveryinformation input latch signal WCDR STROBE. The recovery informationdata storage unit 1264<0:M> or 1264<0:N> stores a data P_WCDR LATCH DATAobtained from the parallel latching through the recovery informationlatch unit 1262 in response to the first internal input strobe signalWCDR PIN<0:M> or the second internal input strobe signal WCDR PIN<0:N>,and provides the stored data as a data P_WCDR OUT DATA to the recoveryinformation data output unit 125 in response to the first internaloutput strobe signal WCDR POUT<0:M> or the second internal output strobesignal WCDR POUT<0:N>.

Herein, regardless of whether the training output command IRDTR isinputted or the predetermined command IWCDR is inputted, when the dataP_WCDR ALIGN DATA corresponding to the recovery information data WCDRDATA or the recovery information training data WCDR TRAIN DATA, which isparallelized based on a one-time input of a command, is inputted onlyonce, a parallel latching operation and an operation of storing theparallel-latched data P_WCDR LATCH DATA are performed once in therecovery information latch unit 1262 and the recovery information datastorage unit 1264<0:M> or 1264<0:N>, respectively. Accordingly, therecovery information data storage unit 1264<0:M> or 1264<0:N> needs aspace for storing one parallel-latched data P_WCDR LATCH DATA.Therefore, one predetermined storage space from among a plurality ofstorage spaces included in the recovery information data storage unit1264<0:M> or 1264<0:N> (which is a space 1264<0> in most cases becauseit begins from the least significant bit (LSB), is used.

However, when the data P_WCDR ALIGN DATA corresponding to the recoveryinformation data WCDR DATA or the recovery information training dataWCDR TRAIN DATA obtained as the training output command IRDTR or thepredetermined command IWCDR is consecutively inputted and parallelized aplurality of times, the recovery information latch unit 1262 of therecovery information storage 126 sequentially latches data P_WCDR ALIGNDATA0, P_WCDR ALIGN DATA1, . . . , P_WCDR ALIGN DATAM or P_WCDR ALIGNDATA0, P_WCDR ALIGN DATA1, . . . , P_WCDR ALIGN DATAN, which correspondto a plurality of recovery information data WCDR DATA0, WCDR DATA1, . .. , WCDR DATAM or WCDR DATA0, WCDR DATA1, . . . , WCDR DATAN, or therecovery information training data WCDR TRAIN DATA0, WCDR TRAIN DATA1, .. . , WCDR TRAIN DATAM or WCDR TRAIN DATA0, WCDR TRAIN DATA1, . . . ,WCDR TRAIN DATAN, in response to consecutive toggling of the recoveryinformation input latch signal WCDR STROBE.

Likewise, the recovery information data storage unit 1264<0:M> or1264<0:N> of the recovery information storage 126 sequentially storesdata P_WCDR LATCH DATA0, P_WCDR LATCH DATA1, . . . , P_WCDR LATCH DATAMor P_WCDR LATCH DATA0, P_WCDR LATCH DATA1, . . . , P_WCDR LATCH DATAN,which are sequentially outputted after being latched in parallel throughthe recovery information latch unit 1262 in response to the sequentialtoggling of a plurality of signals included in the first internal outputstrobe signal WCDR PIN<0:M> or the second internal output strobe signalWCDR PIN<0:N> (WCDR PIN<0>→WCDR PIN<1>→WCDR PIN<2>→ . . . →WCDRPIN<M-1>→WCDR PIN<M> or WCDR PIN<0>→WCDR PIN<1>→WCDR PIN<2>→ . . . →WCDRPIN<N-1>→WCDR PIN<N>), and sequentially provides the stored data to therecovery information data output unit 125 in response to the sequentialtoggling of a plurality of signals included in the first internal outputstrobe signal WCDR POUT<0:M> or the second internal output strobe signalWCDR POUT<0:N> (WCDR POUT<0>→WCDR POUT<1>→WCDR POUT<2>→ . . . →WCDRPOUT<M-1>→WCDR POUT<M> or WCDR OUTP<0>→WCDR POUT<1>→WCDR POUT<2>→ . . .→WCDR POUT<N-1>→WCDR POUT<N>).

When a command is consecutively inputted a plurality of times, which isdescribed above, a parallel latch operation and an operation of storingparallel-latched data P_WCDR LATCH DATA0, P_WCDR LATCH DATA1, . . . ,P_WCDR LATCH DATAM or P_WCDR LATCH DATA0, P_WCDR LATCH DATA1, . . . ,P_WCDR LATCH DATAN are performed a plurality of times in the recoveryinformation latch unit 1262 and the recovery information data storageunit 1264<0:M> or 1264<0:N>, respectively. Therefore, the recoveryinformation data storage unit 1264<0:M> or 1264<0:N> needs a pluralityof storage spaces for respectively storing M or N parallel-latched dataP_WCDR LATCH DATA0, P_WCDR LATCH DATA1, . . . , P_WCDR LATCH DATAM orP_WCDR LATCH DATA0, P_WCDR LATCH DATA1, . . . , P_WCDR LATCH DATAN.

In the first data input/output unit 100, a constituent element 102, forreceiving a normal training data NORMAL TRAIN DATA (whose data window isscanned based on the edge of the source clock ISCK) in response to thetraining input command IWRTR and outputting a signal FB NORMAL TRAINDATA in such a manner that the edge of the data window is synchronizedwith the edge of the source clock ISCK in response to the trainingoutput command IRDTR, has the following structure.

First, the constituent element 102 of the first data input/output unit100 includes a normal input control block 1026, 1023 and 1027, and anormal output control block 1028, 1021 and 1022. The normal inputcontrol block 1026, 1023 and 1027 receives and stores the normaltraining data NORMAL TRAIN DATA at a moment after a time, during whichthe period (TCK) of the source clock ISCK is repeated the first numberof times, elapses from a moment when the training input command IWRTR isinputted. The normal output control block 1028, 1021 and 1022 outputsthe normal training data NORMAL TRAIN DATA stored through the normalinput control block 1026, 1023 and 1027 at a moment after a time, duringwhich the period (TCK) of the source clock ISCK is repeated the secondnumber of times, elapses from a moment when the training output commandIRDTR is inputted.

Herein, the normal input control block 1026, 1023 and 1027 includes anormal input counter 1026, a normal input strobe signal generator 1027,and a normal training data input unit 1023. The normal input counter1026 counts the period (TCK) of the source clock ISCK as many as thefirst number of times from a moment when the training input commandIWRTR is inputted and toggles a normal input enable signal WTEN inresponse to the completion of the counting. The normal input strobesignal generator 1027 generates a normal input strobe signal DIN STROBEin response to a toggling of the normal input enable signal WTEN. Thenormal training data input unit 1023 receives the normal training dataNORMAL TRAIN DATA through the normal data input/output pad 181 andstores it in a predetermined register (which is not directly shown inthe drawings but may be mounted inside the normal training data inputunit 1023) in response to the normal input strobe signal DIN STROBE.

Also, the normal output control block 1028, 1021 and 1022 includes anormal output counter 1021, a normal output strobe signal generator1022, and a normal training data output unit 1028. The normal outputcounter 1021 counts the period of the source clock ISCK as many as thesecond number of times (TCK) from a moment when the training inputcommand IWRTR is inputted and toggles the normal output enable signalRDEN in response to the completion of the counting. The normal outputstrobe signal generator 1022 generates a normal output strobe signalDOUT STROBE in response to the toggling of the normal output enablesignal RDEN. The normal training data output unit 1028 outputs thenormal training data NORMAL TRAIN DATA stored in the predeterminedregister (which is not directly shown in the drawings but may be mountedinside the normal training data input unit 1023) as a feedback normaltraining data FB NORMAL TRAIN DATA through the normal data input/outputpad 181 in response to the normal output strobe signal DOUT STROBE.

In the above-described structure of the semiconductor memory deviceaccording to the embodiment of the present invention, the source clockISCK may include a system clock IHCK for synchronizing the traininginput command IWRTR, the training output command IRDTR, and thepredetermined command IWCDR that are inputted through the command inputpad 182 according to the kind of semiconductor memory device to whichthe exemplary embodiment of the present invention is applied; and a dataclock IWCK for synchronizing the normal data NORMAL DATA, the normaltraining data NORMAL TRAIN DATA and FB NORMAL TRAIN DATA, the recoveryinformation WCDR DATA and FB WCDR DATA, and the recovery informationtraining data WCDR TRAIN DATA and FB WCDR TRAIN DATA that areinputted/outputted through the normal data input/output pad 181 and therecovery information data input/output pad 185.

When the source clock ISCK is divided into the system clock IHCK and thedata clock IWCK, the recovery information input/output controller 122according to the above-described exemplary embodiment of the presentinvention may have the following structure.

The recovery information input/output controller 122 includes a recoveryinformation input control block 1221, 1222, 1223 and 1228 and a recoveryinformation output control block 1224, 1225, 1226 and 1227. The recoveryinformation input control block 1221, 1222, 1223 and 1228 toggles thefirst internal input strobe signal WCDR PIN<0:M> and the second internalinput strobe signal WCDR PIN<0:N> at a moment after a time, during whichthe period (TCK) of the system clock IHCK is repeated the first numberof times, elapses from a moment when the training input command IWRTR orthe predetermined command IWCDR is inputted. The recovery informationoutput control block 1224, 1225, 1226 and 1227 toggles the firstinternal output strobe signal WCDR POUT<0:M> at a moment after a time,during which the period (TCK) of the source clock ISCK is repeated thesecond number of times, elapses from a moment when the training outputcommand IRDTR is inputted, and toggles the second internal output strobesignal WCDR POUT<0:N> at a moment after a time, during which the period(TCK) of the source clock ISCK is repeated the third number of times,elapses from a moment when the first internal input strobe signal WCDRPIN<0:M> and the second internal input strobe signal WCDR PIN<0:N> istoggled.

As described above, although the source clock ISCK is divided into thesystem clock IHCK and the data clock IWCK, the structure of thesemiconductor memory device according to one exemplary embodiment of thepresent invention is not directly changed and if there is anydifference, the data clock IWCK is used for the operation of theconstituent elements for inputting/outputting a data and the systemclock IHCK is used for the operation of the constituent element forinputting a command.

FIG. 2A is a circuit diagram illustrating a training input commandsensor of the semiconductor memory device shown in FIGS. 1A and 1B. FIG.2B is a circuit diagram illustrating a training output command sensor ofthe semiconductor memory device shown in FIGS. 1A and 1B.

Referring to FIGS. 2A and 2B, a training input command sensor 1228 ofthe semiconductor memory device includes a first NAND gate NDS forperforming a NAND operation onto the training input command IWRTR andthe recovery information enable signal WCDR_ENABLE, a second NAND gateND6 for performing a NAND operation onto the training output commandIRDTR and the recovery information enable signal WCDR_ENABLE, a firstinverter INV3 for inverting the phase of the write command IWT, and aset-reset (SR) latch ND7, ND8 and INV4. The set-reset (SR) latch ND7,ND8 and INV4 receives an output signal of the first NAND gate ND5through a set input terminal, receives an output signal of the secondNAND gate ND6 and an output signal of the first inverter INV3 through areset input terminal, inverts the phase of a signal applied to anauxiliary output terminal, and outputs a training input command sensesignal WRTR_FLAG.

In other words, the training input command sensor 1228 of thesemiconductor memory device enables the training input command sensesignal WRTR_FLAG to a logic high level and outputs it in response to thetraining input command IWRTR enabled to a logic high level while therecovery information enable signal WCDR_ENABLE is enabled to a logichigh level and the write command IWT and the training output commandIRDTR are disabled to a logic low level.

Also, the training input command sensor 1228 disables the training inputcommand sense signal WRTR_FLAG to a logic low level and outputs it inresponse to the training output command IRDTR enabled to a logic highlevel, regardless of the logic level of the training input commandIWRTR, while the recovery information enable signal WCDR_ENABLE isenabled to a logic high level and the write command IWT is disabled to alogic low level.

Also, the training input command sensor 1228 disables the training inputcommand sense signal WRTR_FLAG to a logic low level and outputs itregardless of the logic levels of the recovery information enable signalWCDR_ENABLE, the training input command IWRTR, and the training outputcommand IRDTR in response to the write command IWT enabled to a logichigh level.

The training output command sensor 1227 of the semiconductor deviceaccording to the embodiment of the present invention includes a firstNAND gate ND1 for performing a NAND operation onto the training outputcommand IRDTR and the recovery information enable signal WCDR_ENABLE, asecond NAND gate ND2 for performing a NAND operation onto the traininginput command IWRTR and the recovery information enable signalWCDR_ENABLE, a first inverter INV1 for inverting the phase of thepredetermined command IWCDR, and a set-reset (SR) latch ND3, ND4 andINV2. The set-reset (SR) latch ND3, ND4 and INV2 receives an outputsignal of the first NAND gate ND1 through a set input terminal, receivesan output signal of the second NAND gate ND2 and an output signal of thefirst inverter INV1 through a reset input terminal, inverts the phase ofa signal applied to an auxiliary output terminal, and outputs a trainingoutput command sense signal RDTR_FLAG.

In other words, the training output command sensor 1227 among theconstituent elements of the semiconductor memory device enables thetraining output command sense signal RDTR_FLAG to a logic high level andoutputs it in response to the training output command IRDTR enabled to alogic high level while the recovery information enable signalWCDR_ENABLE is enabled to a logic high level and the predeterminedcommand IWCDR and the training input command IWRTR are disabled to alogic low level.

Also, the training output command sensor 1227 disables the trainingoutput command sense signal RDTR_FLAG to a logic low level and outputsit in response to the training output command IRDTR enabled to a logichigh level, regardless of the logic level of the training output commandIRDTR, while the recovery information enable signal WCDR_ENABLE isenabled to a logic high level and the training input command IWRTR isdisabled to a logic low level.

Also, the training output command sensor 1227 disables the trainingoutput command sense signal RDTR_FLAG to a logic low level and outputsit regardless of the logic levels of the recovery information enablesignal WCDR_ENABLE, the training input command IWRTR, and the trainingoutput command IRDTR in response to the predetermined command IWCDRenabled to a logic high level.

FIG. 3A is a circuit diagram illustrating a recovery information (WCDR)input counter of the semiconductor memory device shown in FIGS. 1A and1B.

FIG. 3B is a circuit diagram illustrating a NAND flip flop of therecovery information input counter shown in FIG. 2.

Referring to FIG. 3A, the recovery information input counter 1221 of thesemiconductor memory device according to the exemplary embodiment of thepresent invention includes a first NAND gate ND4 and a first inverterINV4, a plurality of NAND flip flops NAND FLIP FLOP2, NAND FLIP FLOP3,NAND FLIP FLOP4, and NAND FLIP FLOP5, a second inverter INV8, a thirdinverter INV5, a second NAND gate ND1, a third NAND gate ND2, a forthNAND gate ND3, a pass gate PG1, and fourth to sixth inverters INV1, INV2and INV3.

The first NAND gate ND4 and the first inverter INV4 performs an ANDoperation onto the predetermined command IWCDR and the recoveryinformation enable signal WCDR_ENABLE and outputs a counting startcontrol signal WCDRD. The plurality of NAND flip flops NAND FLIP FLOP2,NAND FLIP FLOP3, NAND FLIP FLOP4, and NAND FLIP FLOP5, which areconnected in series to form a chain type structure, receives the sourceclock ISCK as a clock signal, receives any one signal among a pluralityof signals WL<1>, WL<2>, WL<3>, WL<4>, and WL<5> for defining a firstnumber of times, except the least signal WL<1>,and starts to perform anoperation in response to the counting start control signal WCDRD. Thesecond inverter INV8 inverts the phase of a signal IWCDR2B outputtedfrom the rearmost NAND FLIP FLOP2 among the NAND flip flops NAND FLIPFLOP2, NAND FLIP FLOP3, NAND FLIP FLOP4, and NAND FLIP FLOP5 and outputsa signal IWCDR2D. The third inverter INV5 inverts the phase of the leastsignal WL<1> among the plurality of the signals WL<1>, WL<2>, WL<3>,WL<4>, and WL<5> and outputs a signal WLB. The second NAND gate ND1performs a NAND operation onto the counting start control signal WCDRDand the least signal WL<1> among the plurality of the signals WL<1>,WL<2>, WL<3>, WL<4>, and WL<5>. The third NAND gate ND2 performs a NANDoperation onto the output signal IWCDR2D of the second inverter INV8 andthe output signal WLB of the third inverter INV5. The forth NAND gateND3 performs a NAND operation onto an output signal of the second NANDgate ND1 and an output signal of the third NAND gate ND2. The pass gatePG1 synchronizes an output signal of the forth NAND gate ND3 with thesource clock ISCK, which includes CLK and CLKB. The fourth to sixthinverters INV1, INV2 and INV3 latch an output signal outputted from thepass gate PG1 and outputs a recovery information input enable signalWCDRINEN. Also, the recovery information input counter 1221 furtherincludes seventh and eighth inverters INV6 and INV7 for controlling theoperation of the pass gate PG1 by inverting the phase of the sourceclock ISCK so as to output an inverted signal CLKB and performing are-inversion so as to output a signal CLK.

With regards to the operation of the recovery information input counter1221 having the above-described structure, the recovery informationinput counter 1221 starts a counting operation in response to a togglingof the predetermined command IWCDR to a logic high level while therecovery information enable signal WCDR_ENABLE is enabled to a logichigh level.

Herein, the actual number of times of the counting may be differentbased on the logic levels of the plurality of the signals WL<1>, WL<2>,WL<3>, WL<4>, and WL<5> for defining the first number of times.

For example, when a fourth signal WL<4> among the plurality of thesignals WL<1>, WL<2>, WL<3>, WL<4>, and WL<5> is enabled to a logic highlevel and the other signals WL<1>, WL<2>, WL<3>, and WL<5> are disabledto logic low levels, the counting operation begins from the NAND flipflop NAND FLIP FLOP4 corresponding to the fourth signal WL<4> among theNAND flip flops NAND FLIP FLOP2, NAND FLIP FLOP3, NAND FLIP FLOP4, andNAND FLIP FLOP5, and thus the recovery information input enable signalWCDRINEN is enabled to a logic high level in response to the fourthtoggling of the period of the source clock ISCK.

Similarly, when a second signal WL<2> among the plurality of the signalsWL<1>, WL<2>, WL<3>, WL<4>, and WL<5> is enabled to a logic high leveland the other signals WL<1>, WL<3>, WL<4>, and WL<5> are disabled tologic low levels, the counting operation begins from the NAND flip flopNAND FLIP FLOP2 corresponding to the second signal WL<2> among the NANDflip flops NAND FLIP FLOP2, NAND FLIP FLOP3, NAND FLIP FLOP4, and NANDFLIP FLOP5, and thus the recovery information input enable signalWCDRINEN is enabled to a logic high level in response to the secondtoggling of the period of the source clock ISCK.

Referring to FIG. 3B, each of the NAND flip flops NAND FLIP FLOP2, NANDFLIP FLOP3, NAND FLIP FLOP4, and NAND FLIP FLOP5 of the recoveryinformation input counter 1221 may include a first NAND gate ND1, asecond NAND gate ND2, a first pass gate PG1, first and second invertersINV1 and INV2, a second pass gate PG2, and third to fifth invertersINV3, INV4 and INV5. Here, the first NAND gate ND1 performs a NANDoperation onto an input signal IN_SIG (which includes VDD, IWCDR5B,IWCDR4B and IWCDR3B) and any one signal WL<x> among a plurality ofsignals WL<1>, WL<2>, WL<3>, WL<4>, and WL<5> except the least signalWL<1>. The second NAND gate ND2 performs a NAND operation onto an outputsignal of the first NAND gate ND1 and the counting start control signalWCDRD. The first pass gate PG1 passes an output signal of the secondNAND gate ND2 in an enabled duration of the source clock ISCK. The firstand second inverters INV1 and INV2 invert the phase of a signaltransferred from the first pass gate PG1 and latch the inverted signal.The second pass gate PG2 passes the latched signal obtained from thelatching in the first and second inverters INV1 and INV2 in a disabledduration of the source clock ISCK. The third to fifth inverters INV3,INV4 and INV5 latch a signal transferred from the second pass gate PG2and output a signal OUT_ING (which includes IWCDR4B, IWCDR3B, andIWCDR2B). Also, each of the NAND flip flops NAND FLIP FLOP2, NAND FLIPFLOP3, NAND FLIP FLOP4, and NAND FLIP FLOP5 may further include sixthand seventh inverters INV6 and INV7 for controlling the operation of thefirst and second pass gates PG1 and PG2 by inverting the phase of thesource clock ISCK so as to output an inverted signal CLKB and performinga re-inversion so as to output a signal CLK.

Each of the NAND flip flops NAND FLIP FLOP2, NAND FLIP FLOP3, NAND FLIPFLOP4, and NAND FLIP FLOP5 of the recovery information input counter1221 operates as follows.

First, since the signal inputted to the first NAND flip flop NAND FLIPFLOP5 among the plurality of the NAND flip flops NAND FLIP FLOP2, NANDFLIP FLOP3, NAND FLIP FLOP4, and NAND FLIP FLOP5 is power source voltageVDD, an output signal IWCDR5B is disabled to a logic low level inresponse to the fifth signal WL<5> among the plurality of the signalsWL<1>, WL<2>, WL<3>, WL<4>, and WL<5> enabled to a logic high level, andan output signal IWCDR5B is enabled to a logic high level in response tothe fifth signal WL<5> disabled to a logic low level.

The other NAND flip flops NAND FLIP FLOP2, NAND FLIP FLOP3, and NANDFLIP FLOP4 except the foremost NAND flip flop NAND FLIP FLOP5 among theplurality of the NAND flip flops NAND FLIP FLOP2, NAND FLIP FLOP3, NANDFLIP FLOP4, and NAND FLIP FLOP5 may operate differently based on theoutput signals IWCDR3B, IWCDR4B and IWCDR5B outputted from the frontNAND flip flops NAND FLIP FLOP3, NAND FLIP FLOP4, and NAND FLIP FLOP5.

First, when the output signals IWCDR3B, IWCDR4B and IWCDR5B outputtedfrom the front NAND flip flops NAND FLIP FLOP3, NAND FLIP FLOP4, andNAND FLIP FLOP5 are enabled to logic high levels, the other NAND flipflops NAND FLIP FLOP2, NAND FLIP FLOP3, and NAND FLIP FLOP4 except theforemost NAND flip flop NAND FLIP FLOP5 perform the same operation asthat of the foremost NAND flip flop NAND FLIP FLOP5 among the NAND flipflops NAND FLIP FLOP2, NAND FLIP FLOP3, NAND FLIP FLOP4, and NAND FLIPFLOP5. In other words, the logic levels of the output signals IWCDR2B,IWCDR3B and IWCDR4B outputted based on the logic levels of the signalsWL<1>, WL<2>, WL<3>, and WL<4> may become different.

On the other hand, when the signals IWCDR3B, IWCDR4B and IWCDR5Boutputted from the front NAND flip flops NAND FLIP FLOP3, NAND FLIPFLOP4, and NAND FLIP FLOP5 are disabled to logic low levels the outputsignals IWCDR2B, IWCDR3B and IWCDR4B outputted regardless of the logiclevels of the signals WL<1>, WL<2>, WL<3>, and WL<4> are disabled tologic low levels.

Therefore, as shown in the example, when the fourth signal WL<4> isenabled to a logic high level and the other signals WL<1>, WL<2>, WL<3>,and WL<5> are disabled to logic low levels, the NAND flip flop NAND FLIPFLOP4 receiving the fourth signal WL<4> outputs a signal IWCDR5B alwaysenabled to a logic high level, and therefore, does not participate inthe counting operation. Also, the NAND flip flop NAND FLIP FLOP4receiving the fourth signal WL<4> disables the output signal IWCDR4B toa logic low level in response to a toggling of the source clock ISCK.The NAND flip flops NAND FLIP FLOP3 and NAND FLIP FLOP2 receiving thethird signal WL<3> and the second signal WL<2> disable the outputsignals IWCDR3B and IWCDR2B to logic low levels in response to atoggling of the source clock ISCK after the output signals IWCDR4B andIWCDR3B are disabled to logic low levels.

In other words, whenever the source clock ISCK is toggled, the outputsignals IWCDR4B→IWCDR3B→IWCDR2B sequentially outputted from the NANDflip flop NAND FLIP FLOP4 receiving the fourth signal WL<4> to the NANDflip flop NAND FLIP FLOP2 receiving the second signal WL<2> are disabledto logic low levels. The signals are sequentially disabled whenever thesource clock ISCK is toggled, as described above, and when the signalIWCDR2B outputted from the rearmost NAND flip flop NAND FLIP FLOP2 isdisabled to a logic low level, the recovery information input enablesignal WCDRINEN is enabled to a logic high level in response to atoggling of the next source clock ISCK. Therefore, it is possible toenable the recovery information input enable signal WCDRINEN to a logichigh level at a moment when the source clock ISCK is toggled four timesin response to the fourth signal WL<4> enabled to a logic high level.

FIG. 4 is a circuit diagram illustrating a recovery information inputlatch signal toggling unit of the semiconductor memory device shown inFIGS. 1A and 1B.

Referring to FIG. 4, the recovery information input latch signaltoggling unit 1222 of the semiconductor memory device according to theembodiment of the present invention includes a plurality of invertersINV1, INV2, INV3 and INV4 serially connected to each other for receivingthe recovery information input enable signal WCDRINEN outputted from therecovery information input counter 1221 and outputs the recoveryinformation input enable signal WCDRINEN as a recovery information inputlatch signal WCDR STROBE with a predetermined time difference set upwhile maintaining its phase.

FIG. 5 is a circuit diagram illustrating first and second recoveryinformation output enable signal toggling controllers of thesemiconductor memory device shown in FIGS. 1A and 1B.

Referring to FIG. 5, the first and second recovery information outputenable signal toggling controllers 1224 of the semiconductor memorydevice according to the exemplary embodiment of the present inventionperforms an operation of a first recovery information output enablesignal toggling controller 1224 and an operation of a second recoveryinformation output enable signal toggling controllers 1224 based on thelogic levels of the training input command sense signal WRTR_FLAG andthe training output command sense signal RDTR_FLAG.

In other words, when the training output command IRDTR is inputted andthe training output command sense signal RDTR_FLAG is enabled to a logichigh level and the training input command sense signal WRTR_FLAG isdisabled to a logic low level, the first recovery information outputenable signal toggling controller 1224 performs an operation fortoggling the recovery information output enable signal WCDROUTEN inresponse to a normal output enable signal RDEN (which is toggled at amoment when the period of the source clock ISCK is counted two times)outputted from the normal output counter 1021.

On the other hand, when the predetermined command IWCDR is inputted andthe training output command sense signal RDTR_FLAG is disabled to alogic low level and the training input command sense signal WRTR_FLAG isenabled to a logic high level, the second recovery information outputenable signal toggling controller 1224 counts the period of the sourceclock ISCK in the third number of times in response to a toggling of therecovery information input enable signal WCDRINEN outputted from therecovery information input counter 1221 and performs an operation fortoggling the recovery information output enable signal WCDROUTEN inresponse to completion of the counting.

To be specific, the first and second recovery information output enablesignal toggling controllers 1224 may include a first NOR gate NOR1, afirst inverter INV5, a first NAND gate ND5 and a second inverter INV4, asecond NAND gate ND8 and a third inverter INV9, a third NAND gate ND1, aplurality of NAND flip flops NAND FLIP FLOP6, NAND FLIP FLOP7, and NANDFLIP FLOP8, a fourth inverter INV10, a fourth NAND gate ND6 and a fifthinverter INV6, a second NOR gate NOR2, a fifth NAND gate ND2, a sixthNAND gate ND3, a seventh NAND gate ND4, a pass gate PG1, sixth to eighthinverters INV1, INV2 and INV3. Also, the first and second recoveryinformation output enable signal toggling controllers 1224 may furtherinclude ninth and tenth inverters INV7 and INV8 for controlling anoperation of the pass gate PG1 by inverting the phase of the sourceclock ISCK so as to output an output signal CLKB and performing are-inversion so as to output an output signal CLK.

The first NOR gate NOR1 performs a NOR operation onto the training inputcommand sense signal WRTR_FLAG and the training output command sensesignal RDTR_FLAG and outputs a first training mixed sense signalTRAIN_FLAGB. The first inverter INV5 inverts the phase of the firsttraining mixed sense signal TRAIN_FLAGB and outputs a second trainingmixed sense signal TRAIN_FLAGD. The first NAND gate ND5 and the secondinverter INV4 perform an AND operation onto the first training mixedsense signal TRAIN_FLAGB, the recovery information input enable signalWCDRINEN, and the recovery information enable signal WCDR_ENABLE andoutput a mixed recovery information input enable signal WCDRINEND. Thesecond NAND gate ND7 and the third inverter INV9 perform an ANDoperation onto the training output command sense signal RDTR_FLAG andthe recovery information enable signal WCDR_ENABLE and output a mixedtraining output command sense signal RDTR_FLAGD. The third NAND gate ND1performs a NAND operation onto the normal output enable signal RDEN andthe mixed training output command sense signal RDTR_FLAGD, The pluralityof the NAND flip flops NAND FLIP FLOP6, NAND FLIP FLOP7, and NAND FLIPFLOP8, which are connected in series to form a chain type structure,receive the source clock ISCK as a clock signal, receive as an inputcontrol signal any one signal except the least signal WCDRL<5> among aplurality of signals WCDRL<5>, WCDRL<6>, WCDRL<7> and WCDRL<8> fordefining a third number of times, and begin operating in response to themixed recovery information input enable signal WCDRINEND. The fourthinverter INV10 inverts the phase of a signal WCDR6B outputted from therearmost NAND flip flop NAND FLIP FLOP6 among the plurality of the NANDflip flops NAND FLIP FLOP6, NAND FLIP FLOP7, and NAND FLIP FLOP8 andoutputs a signal WCDR6D. The fourth NAND gate ND6 and the fifth inverterINV6 perform an AND operation onto the least signal WCDRL<5> among theplurality of the signals WCDRL<5>, WCDRL<6>, WCDRL<7> and WCDRL<8> fordefining the third number of times and the first training mixed sensesignal TRAIN_FLAGB and output a first least number defining signalWCDRL5D. The second NOR gate NOR2 performs a NOR operation onto thefirst least number defining signal WCDRL5D and the second training mixedsense signal TRAIN_FLAGD and outputs a second least number definingsignal WCDRL5B. The fifth NAND gate ND2 performs a NAND operation ontothe mixed recovery information input enable signal WCDRINEND and thefirst least number defining signal WCDRL5D. The sixth NAND gate ND3performs a NAND operation onto the output signal WCDR6D of the fourthinverter INV10 and the second least number defining signal WCDRL5B. Theseventh NAND gate ND4 performs a NAND operation onto an output signal ofthe third NAND gate ND1, an output signal of the fifth NAND gate ND5,and an output signal of the sixth NAND gate ND6. The pass gate PG1synchronizes an output signal of the seventh NAND gate ND4 with thesource clock ISCK. The sixth to eighth inverters INV1, INV2 and INV3latch an output signal outputted from the pass gate PG1 and outputs therecovery information output enable signal WCDROUTEN.

To have a look at the operations of the first and second recoveryinformation output enable signal toggling controllers 1224, the firstand second recovery information output enable signal togglingcontrollers 1224 toggles the recovery information output enable signalWCDROUTEN to a logic high level, regardless of the logic level of thetraining input command sense signal WRTR_FLAG in response to a togglingof the normal output enable signal RDEN being toggled to a logic highlevel while the recovery information enable signal WCDR_ENABLE isenabled to a logic high level and the training output command sensesignal RDTR_FLAG is enabled to a logic high level.

When the training input command sense signal WRTR_FLAG is enabled to alogic high level and the training output command sense signal RDTR_FLAGis disabled to a logic low level while the recovery information enablesignal WCDR_ENABLE is enabled to a logic high level, a countingoperation begins in response to a toggling of the recovery informationinput enable signal WCDRINEN to a logic high level.

Herein, the actual number of times of the counting operations may bedifferent based on the logic levels of the plurality of the signalsWCDRL<5>, WCDRL<6>, WCDRL<7> and WCDRL<8> for defining the third numberof times.

For example, when a seventh signal WCDRL<7> is enabled to a logic highlevel and the other signals WCDRL<5>, WCDRL<6>, and WCDRL<8> aredisabled to logic low levels, the counting operation starts from a NANDflip flop NAND FLIP FLOP7 which receives the seventh signal WCDRL<7> andthe recovery information output enable signal WCDROUTEN is enabled to alogic high level in response to the third toggling of the period of thesource clock ISCK.

Similarly, when a sixth signal WCDRL<6> is enabled to a logic high leveland the other signals WCDRL<5>, WCDRL<7>, and WCDRL<8> are disabled tologic low levels, the counting operation starts from a NAND flip flopNAND FLIP FLOP6 which receives the sixth signal WCDRL<6> and therecovery information input enable signal WCDRINEN is enabled to a logichigh level in response to the second toggling of the period of thesource clock ISCK.

FIG. 6A is a circuit diagram illustrating an internal input strobesignal toggling unit of the semiconductor memory device shown in FIGS.1A and 1B. FIG. 6B is a circuit diagram illustrating a plurality ofserial flip flops of the internal input strobe signal toggling unitshown in FIG. 6A. FIG. 6C is a circuit diagram illustrating a feedbackflip flop of the internal input strobe signal toggling unit shown inFIG. 6A.

Referring to FIG. 6A, the internal input strobe signal toggling unit1223 of the semiconductor memory device according to the embodiment ofthe present invention includes a plurality of serial flip flops DFFRB1,DFFRB2, . . . , DFFRBM or DFFRBN connected to each other to form a chaintype structure, one feedback flip flop DFFSB, and a plurality ofinternal input strobe signal generators PIN GEN0, PIN GEN1, PIN GEN2, .. . , PIN GENM or PIN GENN. The plurality of the serial flip flopsDFFRB1, DFFRB2, . . . , DFFRBM or DFFRBN and the feedback flip flopDFFSB count a plurality of output control signals Q<0>, Q<1>, Q<2>, . .. , Q<M> or Q<N>, circling the plurality of the output control signalsin a predetermined number of times ( . . . →Q<M> or Q<N>→Q<0>→Q<1>→Q<2>→. . . →Q<M> or Q<N>→Q<0>→ . . . ) in response to a toggling of therecovery information input latch signal WCDR STROBE. The plurality ofthe internal input strobe signal generators PIN GEN0, PIN GEN1, PINGEN2, . . . , PIN GENM or PIN GENN generate a first internal inputstrobe signal WCDR PIN<0:M> or a second internal input strobe signalWCDR PIN<0:N> in response to any one signal among the plurality of theoutput control signals Q<0>, Q<1>, Q<2>, . . . , Q<M> or Q<N> and therecovery information input latch signal WCDR STROBE.

Herein, each of the plurality of the internal input strobe signalgenerators PIN GEN0, PIN GEN1, PIN GEN2, . . . , PIN GENM or PIN GENNincludes a NAND gate ND1 for performing a NAND operation onto therecovery information input latch signal WCDR STROBE and any one signalQ<X> among the plurality of the output control signals Q<0>, Q<1>, Q<2>,. . . , Q<M> or Q<N>, and a plurality of inverters INV1, INV2 and INV3for inverting the phase of a signal outputted from the NAND gate ND1,delaying the signal for a certain period of time, and outputting thedelayed signal as any one signal WCDR PIN<x> among the first internalinput strobe signals WCDR PIN<0:M> and the second internal input strobesignals WCDR PIN<0:N>.

The plurality of the serial flip flops DFFRB1, DFFRB2, . . . , DFFRBM orDFFRBN and the feedback flip flop DFFSB initialize its operation inresponse to a reset signal RESETB, and accordingly, all of the pluralityof the output control signals Q<0>, Q<1>, Q<2>, . . . , Q<M> or Q<N> areinitialized.

In FIG. 6A, it is shown that the constituent elements for generating thefirst internal input strobe signals WCDR PIN<0:M> and the constituentelements for generating the second internal input strobe signals WCDRPIN<0:N> are overlapped. If the value M and the value N are the same,there is no problem in overlapping the constituent elements. However,generally the value M and the value N are different, and thus, theconstituent elements for generating the first internal input strobesignals WCDR PIN<0:M> and the constituent elements for generating thesecond internal input strobe signals WCDR PIN<0:N> may be independent.Of course, the constituent elements may be different according to thedesign intention of a designer. They may be designed to be the same asshown in the drawing, or some constituent elements may be shared and theother constituent elements may not be shared.

Referring to FIG. 6B, the feedback flip flop DFFSB illustrated in FIG.6A includes a first pass gate PG1, a NOR gate NOR1 and a first inverterINV3, a second pass gate PG2, and second and third inverters INV4 andINV5. The first pass gate PG1 passes a signal applied through an inputterminal D in an enabled duration of the recovery information inputlatch signal WCDR STROBE. The NOR gate NOR1 and the first inverter INV3latch and output a signal transferred through the first pass gate PG1 ina phase-inverted state or initializes the signal to a logic low leveland outputs it in response to an inverted reset signal RESET. The secondpass gate PG2 passes the latched signal obtained from the NOR gate NOR1and the first inverter INV3 in a disabled duration of the source clockISCK. The second and third inverters INV4 and INV5 latch a signaltransferred through the second pass gate PG2 in a phase inverted stateand transfer the latched signal to an output terminal Q.

Referring to FIG. 6C, each of the plurality of the serial flip flopsDFFRB1, DFFRB2, . . . , DFFRBM or DFFRBN illustrated in FIG. 6A mayinclude a first pass gate PG1, a NAND gate ND1 and a first inverterINV2, a second pass gate PG2, and second and third inverters INV3 andINV4. The first pass gate PG1 passes a signal applied through an inputterminal D in an enabled duration of the recovery information inputlatch signal WCDR STROBE. The NAND gate ND1 and the first inverter INV2latch and output a signal transferred through the first pass gate PG1 ina phase-inverted state or initialize the signal to a logic high leveland output it in response to a reset signal RESETB. The second pass gatePG2 passes the latched signal obtained from the NAND gate ND1 and thefirst inverter INV2 in a disabled duration of the recovery informationinput latch signal WCDR STROBE. The second and third inverters INV3 andINV4 latch a signal transferred through the second pass gate PG2 in aphase inverted state and transfer the latched signal to an outputterminal Q.

FIG. 7A is a circuit diagram illustrating an internal output strobesignal toggling unit of the semiconductor memory device shown in FIGS.1A and 1B. FIG. 7B is a circuit diagram illustrating each of a pluralityof internal output strobe signal generators shown in FIG. 7A. FIG. 7C isa circuit diagram illustrating each of a plurality of serial flip flopsof the internal output strobe signal toggling unit shown in FIG. 7A.FIG. 7D is a circuit diagram illustrating one feedback flip flop of theinternal output strobe signal toggling unit shown in FIG. 7A.

Referring to FIG. 7A, the internal output strobe signal toggling unit1225 of the semiconductor memory device according to an exemplaryembodiment of the present invention includes a plurality of serial flipflops DPFFRB1, DPFFRB2, . . . , DPFFRBM or DPFFRBN connected to eachother to form a chain type structure, one feedback flip flop DPFFSB, anda plurality of internal output strobe signal generators POUT GEN0, POUTGEN1, POUT GEN2, . . . , POUT GENM or POUT GENN. The plurality of theserial flip flops DPFFRB1, DPFFRB2, . . . , DPFFRBM or DPFFRBN and thefeedback flip flop DPFFSB count a plurality of counting control signalsC<0>, C<1>, C<2>, . . . , C<M> or C<N>, circling the plurality of thecounting control signals in a predetermined period ( . . . →C<M> orC<N>→C<0>→C<1>→C<2>→ . . . →C<M> or C<N>→C<0>→ . . . ) in response to atoggling of the recovery information output enable signal WCDROUTEN, andgenerates a plurality of output control signals P<0>, P<1>, P<2>, . . ., P<M> or P<N> corresponding to the counting. The plurality of theinternal output strobe signal generators POUT GEN0, POUT GEN1, POUTGEN2, . . . , POUT GENM or POUT GENN generate a first internal outputstrobe signal WCDR POUT<0:M> or a second internal output strobe signalWCDR POUT<0:N> in response to any one signal among the plurality of theoutput control signals P<0>, P<1>, P<2>, . . . , P<M> or P<N> and thesource clock ISCK.

Referring to FIG. 7B, each of the plurality of the internal outputstrobe signal generators POUT GEN0, POUT GEN1, POUT GEN2, . . . , POUTGENM or POUT GENN includes a first pass gate PG1, first and secondinverters INV1 and INV2, a second pass gate PG2, and third and fourthinverters INV3 and INV4. The first pass gate PG1 passes any one signalQ<X> among the plurality of the output control signals P<0>, P<1>, P<2>,. . . , P<M> or P<N> in an enabled duration of the source clock ISCK.The first and second inverters INV1 and INV2 invert the phase of asignal transferred through the first pass gate PG1 and latch theinverted signal. The second pass gate PG2 passes the latched signalobtained from the first and second inverters INV1 and INV2 in a disabledduration of the source clock ISCK. The third and fourth inverters INV3and INV4 latch a signal transferred through the second pass gate PG2,invert the phase of the latched signal, and output the latched signal asa first internal output strobe signal WCDR POUT<0:M> or a secondinternal output strobe signal WCDR POUT<0:N>. Also, each of theplurality of the internal output strobe signal generators POUT GEN0,POUT GEN1, POUT GEN2, . . . , POUT GENM or POUT GENN may further includea fifth inverter INV5 for controlling the operations of the first andsecond pass gates PG1 and PG2 by inverting the phase of the source clockISCK so as to output a signal ISCKB.

The plurality of the serial flip flops DPFFRB1, DPFFRB2, . . . , DPFFRBMor DPFFRBN and the feedback flip flop DPFFSB are initialized in responseto a reset signal RESETB, and accordingly, all of the plurality of thecounting control signals C<0>, C<1>, C<2>, . . . , C<M> or C<N> and theplurality of the output control signals P<0>, P<1>, P<2>, . . . , P<M>or P<N> are initialized.

In FIG. 7A, it is shown that the constituent elements for generating thefirst internal output strobe signals WCDR POUT<0:M> and the constituentelements for generating the second internal output strobe signals WCDRPOUT<0:N> are overlapped. If the value M and the value N are the same,there is no problem in overlapping the constituent elements. However,generally the value M and the value N are different, and thus, theconstituent elements for generating the first internal output strobesignals WCDR POUT<0:M> and the constituent elements for generating thesecond internal output strobe signals WCDR POUT<0:N> may be independent.Of course, the constituent elements may be different according to thedesign intention of a designer. They may be designed to be the same asshown in the drawing, or some constituent elements may be shared and theother constituent elements may not be shared.

Referring to FIG. 7C, the feedback flip flop DPFFSB illustrated in FIG.7A includes a first pass gate PG1, a NAND gate ND1 and a first inverterINV2, second and third inverters INV5 and INV6, a second pass gate PG2,and fourth and fifth inverters INV3 and INV4. The first pass gate PG1passes a signal applied through an input terminal D in an enabledduration of the recovery information output enable signal WCDROUTEN. TheNAND gate ND1 and the first inverter INV2 latch and output a signaltransferred through the first pass gate PG1 in a phase-inverted state orinitialize the signal to a logic high level and output it in response toa reset signal RESETB.

The second and third inverters INV5 and INV6 drive a signal outputtedthrough the first inverter INV2 to an output control signal outputterminal P. The second pass gate PG2 passes the latched signal obtainedfrom the NAND gate ND1 and the first inverter INV2 in a disabledduration of the recovery information output enable signal WCDROUTEN. Thefourth and fifth inverters INV3 and INV4 latch a signal transferredthrough the second pass gate PG2 in a phase-inverted state and transferthe latched signal to a counting control signal output terminal C.

Referring to FIG. 7D, each of the serial flip flops DPFFRB1, DPFFRB2, .. . , DPFFRBM or DPFFRBN illustrated in FIG. 7A may include a first passgate PG1, a NOR gate NOR1 and a first inverter INV3, second and thirdinverters INV6 and INV7, a second pass gate PG2, and fourth and fifthinverters INV4 and INV5. The first pass gate PG1 passes a signal appliedthrough an input terminal D in an enabled duration of recoveryinformation output enable signal WCDROUTEN. The NOR gate NOR1 and thefirst inverter INV3 latch and output a signal transferred through thefirst pass gate PG1 in a phase-inverted state or initialize the signalto a logic low level and output it in response to an inverted resetsignal RESET. The second and third inverters INV6 and INV7 drive asignal outputted through the first inverter INV3 to an output controlsignal output terminal P. The second pass gate PG2 passes the latchedsignal obtained from the NOR gate NOR1 and the first inverter INV3 in adisabled duration of the recovery information output enable signalWCDROUTEN. The fourth and fifth inverters INV4 and INV5 latch a signaltransferred through the second pass gate PG2 in a phase-inverted stateand transfer the latched signal to a counting control signal outputterminal C.

FIG. 8A is a circuit diagram illustrating a recovery information outputdriver enable signal toggling unit of the semiconductor memory deviceshown in FIGS. 1A and 1B. FIG. 8B is circuit diagram illustrating aplurality of serial flip flops of the recovery information output driverenable signal toggling unit shown in FIG. 1A.

Referring to FIG. 8A, the recovery information output driver enablesignal toggling unit 1226 of the semiconductor memory device includes aplurality of serial flip flops DFFB1, DFFB2, . . . , DFFBM or DFFBNconnected to each other to form a chain type structure, a NAND gate ND1and a first inverter INV1, a first pass gate PG1, and second and thirdinverters INV2 and INV3. The plurality of serial flip flops DFFB1,DFFB2, . . . , DFFBM or DFFBN sequentially toggle a plurality of bitoutput control signals A<1>, A<2>, A<3>, and A<4> in response to atoggling of the recovery information output enable signal WCDROUTENwhenever the source clock ISCK is toggled. The NAND gate ND1 and thefirst inverter INV1 receive the plurality of the bit output controlsignals A<1>, A<2>, A<3>, and A<4> and perform an AND operation. Thefirst pass gate PG1 passes a signal outputted through the NAND gate ND1and the first inverter INV1 in an enabled duration of the source clockISCK. The second and third inverters INV2 and INV3 latch a signaltransferred through the pass gate PG1, invert the phase, and output arecovery information output driver enable signal WCDR DOUT ENABLE. Also,the recovery information output driver enable signal toggling unit 1226further includes a fourth inverter INV4 for controlling the operation ofthe pass gate PG1 by inverting the phase of the source clock ISCK so asto output a signal ISCKB.

Referring to FIG. 8B, each of the plurality of the serial flip flopsDFFB1, DFFB2, DFFB3, and DFFB4 may include a first pass gate PG1, firstand second inverter INV1 and INV2, a second pass gate PG2, and third tofifth inverters INV3, INV4 and INV 5. The first pass gate PG1 passes asignal applied through an input terminal D in an enabled duration of thesource clock ISCK. The first and second inverter INV1 and INV2 latch andoutput a signal transferred through the first pass gate PG1 in aphase-inverted state. The second pass gate PG2 passes the latched signalobtained from the first and second inverter INV1 and INV2 in a disabledduration of the source clock ISCK. The third to fifth inverters INV3,INV4 and INV 5 latch a signal transferred through the second pass gatePG2 in a phase-inverted state and transfer the latched signal to aninversion output terminal QB. Also, each of the plurality of the serialflip flops DFFB1, DFFB2, DFFB3, and DFFB4 may further include a sixthinverter INV6 for controlling the operations of the first and secondpass gates PG1 and PG2 by inverting the source clock ISCK so as tooutput an inverted source clock ISCKB.

FIG. 9 is a block diagram illustrating a semiconductor system includingthe semiconductor memory device shown in FIGS. 1A and 1B.

Referring to FIG. 9, a semiconductor system including a semiconductormemory device 200 and a semiconductor memory device controller 300 andinputs/outputs a normal data NORMAL DATA and recovery information dataWCDR DATA between the semiconductor memory device 200 and thesemiconductor memory device controller 300. The semiconductor memorydevice controller 300 transfers recovery information training data WCDRTRAIN DATA to the semiconductor memory device 200 at a first momentdetermined according to a training input command IWRTR generatedinternally, and controls the phase of the recovery information data WCDRDATA transferred to the semiconductor memory device 200 in response to afeedback recovery information training data FB WCDR TRAIN DATA appliedfrom the semiconductor memory device 200 at a second moment determinedaccording to the training output command IRDTR generated internally. Thesemiconductor memory device 200 receives the recovery informationtraining data WCDR TRAIN DATA from the semiconductor memory devicecontroller 300 at a first moment determined according to the traininginput command IWRTR, and transfers a feedback recovery informationtraining data FB WCDR TRAIN DATA to the semiconductor memory devicecontroller 300 at a second moment determined according to the trainingoutput command IRDTR.

Herein, the semiconductor memory device controller 300 includes arecovery information training comparison unit 310, a recoveryinformation training generation unit 315, a recovery information datageneration unit 320, a normal training comparison unit 330, a normaltraining generation unit 335, a recovery information comparison unit340, a normal data generation unit 350, a normal data input/output pad360, a command output pad 370, a recovery information data input/outputpad 380, a clock output pad 390, a command generation unit 302, and aclock generation unit 304.

The semiconductor memory device 200 includes a first data input/outputunit 210, a second data input/output unit 220, a normal datainput/output unit 230, a recovery information data input/output unit240, a core region 250, a normal data input/output pad 260, a commandinput pad 270, a recovery information data input/output pad 280, a clockinput pad 290, a memory register set (MRS) 202, and a command decoder204.

To be specific, the command generation unit 302 of the semiconductormemory device controller 300 generates the training input command IWRTR,the training output command IRDTR, and the predetermined command IWCDR.

Also, the recovery information training comparison unit 310 of thesemiconductor memory device controller 300 compares the data value ofthe recovery information training data WCDR TRAIN DATA with the datavalue of the feedback recovery information training data FB WCDR TRAINDATA, and generates a comparison signal WCDR TR COMP based on thecomparison result.

Further, the recovery information data generation unit 320 of thesemiconductor memory device controller 300 generates the recoveryinformation data WCDR DATA corresponding to the predetermined commandIWCDR while changing the phase based on the comparison signal WCDR TRCOMP.

The normal training comparison unit 330 of the semiconductor memorydevice controller 300 compares a data value of a normal training dataNORMAL TRAIN DATA with a data value of a feedback normal training dataFB NORMAL TRAIN DATA, and generates a normal training comparison signalNORMAL TR COMP.

The recovery information comparison unit 340 of the semiconductor memorydevice controller 300 compares a data value of a recovery informationdata WCDR DATA with a data value of a feedback recovery information dataFB WCDR DATA, and generates a recovery information comparison signalWCDR COMP.

The normal data generation unit 350 of the semiconductor memory devicecontroller 300 generates a normal data NORMAL DATA in response to awrite command IWT, and the phase of the generated normal data NORMALDATA is changed based on the normal training comparison signal NORMAL TRCOMP or the recovery information comparison signal WCDR COMP.

Therefore, the command output pad 370 of the semiconductor memory devicecontroller 300 outputs a training input command IWRTR, a training outputcommand IRDTR, and a predetermined command IWCDR.

Likewise, the normal data input/output pad 360 of the semiconductormemory device controller 300 inputs/outputs a normal data NORMAL DATA, anormal training data NORMAL TRAIN DATA, and a feedback normal trainingdata FB NORMAL TRAIN DATA. The recovery information data input/outputpad 380 of the semiconductor memory device controller 300 inputs/outputsa recovery information data WCDR DATA, a feedback recovery informationdata FB WCDR DATA, a recovery information training data WCDR TRAIN DATA,and a feedback recovery information training data FB WCDR TRAIN DATA.

The clock output pad 390 of the semiconductor memory device controller300 outputs a source clock ISCK.

The first data input/output unit 210 of the semiconductor memory device200 receives and stores the normal training data NORMAL TRAIN DATA inresponse to the training input command IWRTR, and outputs the feedbacknormal training data FB NORMAL TRAIN DATA in response to the trainingoutput command IRDTR.

The second data input/output unit 220 of the semiconductor memory device200 receives and stores the recovery information training data WCDRTRAIN DATA in response to the training input command IWRTR, and outputsthe feedback recovery information training data FB WCDR TRAIN DATA inresponse to the training output command IRDTR.

The normal data input/output unit 230 of the semiconductor memory device200 receives and stores a normal data NORMAL DATA in response to a readcommand IRD, and outputs the stored normal data NORMAL DATA in responseto a write command IWT.

The recovery information data input/output unit 240 of the semiconductormemory device 200 receives and stores a recovery information data WCDRDATA in response to the predetermined command IWCDR, and outputs afeedback recovery information data FB WCDR DATA after a certain time.

The command input pad 270 of the semiconductor memory device 200receives the training input command IWRTR, the training output commandIRDTR, and the predetermined command IWCDR.

The normal data input/output pad 260 of the semiconductor memory device200 inputs/outputs a normal data NORMAL DATA, a normal training dataNORMAL TRAIN DATA, and a feedback normal training data FB NORMAL TRAINDATA.

The recovery information data input/output pad 280 of the semiconductormemory device 200 inputs/outputs a recovery information data WCDR DATA,a feedback recovery information data FB WCDR DATA, a recoveryinformation training data WCDR TRAIN DATA, and a feedback recoveryinformation training data FB WCDR TRAIN DATA.

The clock input pad 290 of the semiconductor memory device 200 receivesthe source clock ISCK.

Since the semiconductor memory device 200 and the semiconductor memorydevice controller 300 have the above-described structures, a clocktransfer path 430, a command transfer path 400, a normal data transferpath 410, and a recovery information data transfer path 420 may bedisposed between the semiconductor memory device 200 and thesemiconductor memory device controller 300. The clock transfer path 430transfers the source clock ISCK. The command transfer path 400 transfersthe training input command IWRTR, the training output command IRDTR, thepredetermined command IWCDR. The normal data transfer path 410 transfersthe normal data NORMAL DATA in response to data read/write commandIWT/IRD, and transfers the normal training data NORMAL TRAIN DATA andthe feedback normal training data FB NORMAL TRAIN DATA in response tothe training input command IWRTR and the training output command IRDTR.The recovery information data transfer path 420 transfers the feedbackrecovery information data FB WCDR DATA in response to the predeterminedcommand IWCDR, and transfers the recovery information training data WCDRTRAIN DATA and the feedback recovery information training data FB WCDRTRAIN DATA in response to the training input command IWRTR and thetraining output command IRDTR.

The source clock ISCK transferred through the clock transfer path 430includes a system clock IHCK and a data clock IWCK. The system clockIHCK is used for synchronization with the training input command IWRTR,the training output command IRDTR, and the predetermined command IWCDR.The data clock IWCK is used for synchronization of a normal data NORMALDATA, a normal training data NORMAL TRAIN DATA, a feedback normaltraining data FB NORMAL TRAIN DATA, a recovery information data WCDRDATA, a recovery information training data WCDR TRAIN DATA, and afeedback recovery information training data FB WCDR TRAIN DATA.

The semiconductor memory device controller 300 transfers the normaltraining data NORMAL TRAIN DATA generated in the normal traininggeneration unit 335 at a moment determined according to the traininginput command IWRTR, which is generated in the command generation unit302, to the semiconductor memory device 200 through the normal datainput/output pad 360; controls the phase of the normal data NORMAL DATAgenerated in the normal data generation unit 350 and transfers thephase-controlled data to the semiconductor memory device 200 through thenormal data input/output pad 360 in response to the feedback normaltraining data FB NORMAL TRAIN DATA, which is supplied by thesemiconductor memory device 200 through the normal data input/output pad360 at a second moment corresponding to the training output commandIRDTR generated in the command generation unit 302.

The semiconductor memory device controller 300 transfers the recoveryinformation data WCDR DATA to the semiconductor memory device 200through the recovery information data input/output pad 280 at a firstmoment determined according to the predetermined command IWCDR, which isone of the signals generated in the command generation unit 302; andcontrols the phase of the normal data NORMAL DATA generated in thenormal data generation unit 350 in response to the feedback recoveryinformation data FB WCDR DATA applied from the semiconductor memorydevice 200 through the recovery information data input/output pad 280after a certain time passes from the moment of the transfer, andtransfers the phase-controlled data to the semiconductor memory device200 through the normal data input/output pad 360.

Herein, the recovery information comparison unit 340 of thesemiconductor memory device controller 300 compares a data value of therecovery information data WCDR DATA and a data value of the feedbackrecovery information data FB WCDR DATA, and transfers the comparisonresult to the normal data generation unit 350. The normal datageneration unit 350 receives the comparison result and controls thephase of the normal data NORMAL DATA transferred to the semiconductormemory device 200 based on the value of the output signal of therecovery information comparison unit 340, which is a signal WCDR COMP.

The semiconductor memory device 200 receives the normal training dataNORMAL TRAIN DATA from the semiconductor memory device controller 300through the normal data input/output pad 260 at a first momentdetermined based on the training input command IWRTR applied through thecommand input pad 270, and transfers a feedback normal training data FBNORMAL TRAIN DATA through the normal data input/output pad 260 at asecond moment determined based on the training output command IRDTR,which is applied through the normal data input/output pad 260, andtransfers the feedback normal training data FB NORMAL TRAIN DATA to thesemiconductor memory device controller 300.

The semiconductor memory device 200 receives the recovery informationdata WCDR DATA from the semiconductor memory device controller 300through the recovery information data input/output pad 280 at a firstmoment determined based on the predetermined command IWCDR, which is oneof the signals generated in the command generation unit 302, andtransfers the feedback recovery information data FB WCDR DATA to thesemiconductor memory device controller 300 through the recoveryinformation data input/output pad 280 after a certain time passes fromthe moment of receiving the recovery information data WCDR DATA.

The recovery information training data WCDR TRAIN DATA and the normaltraining data NORMAL TRAIN DATA which are transferred from thesemiconductor memory device controller 300 to the semiconductor memorydevice 200 are in a state where the data window is scanned based on anedge of the source clock ISCK.

A method of applying a signal by scanning its data window based on anedge of a source clock ISCK, which is a method of transferring therecovery information training data WCDR TRAIN DATA and the normaltraining data NORMAL TRAIN DATA between the semiconductor memory devicecontroller 300 and the semiconductor memory device 200, is describedherein with reference to FIG. 12.

According to the method, a point corresponding to the edge of the sourceclock ISCK is sequentially changed at a predetermined interval from astarting point to an end point within the range of a data windowcorresponding to a plurality of bits, which are included in each of thenormal training data NORMAL TRAIN DATA and the recovery informationtraining data WCDR TRAIN DATA.

When the normal training data NORMAL TRAIN DATA and the recoveryinformation training data WCDR TRAIN DATA provided through a method ofscanning their data windows are stored in a predetermined space insidethe semiconductor device under the assumption that the edge of thesource clock ISCK is a center point of each data window, and the datavalues of the normal training data NORMAL TRAIN DATA and the recoveryinformation training data WCDR TRAIN DATA are detected in thesemiconductor memory device controller 300, it is possible to detectfrom the detection result the location of the exact center pointcorresponding to the edge of the source clock ISCK in the data window ofthe normal training data NORMAL TRAIN DATA and the recovery informationtraining data WCDR TRAIN DATA, which are transferred between thesemiconductor memory device 200 and the semiconductor memory devicecontroller 300.

As for the recovery information data WCDR DATA transferred from thesemiconductor memory device controller 300 to the semiconductor memorydevice 200, the edges of the data windows are synchronized with the edgeof the source clock ISCK. As for the training input command IWRTR andthe training output command IRDTR and the predetermined command IWCDRand the normal data NORMAL DATA, the centers of the data windows aresynchronized with the edge of the source clock ISCK.

As for the feedback recovery information training data FB WCDR TRAINDATA and the feedback normal training data FB NORMAL TRAIN DATA and thefeedback recovery information data FB WCDR DATA and the normal dataNORMAL DATA, which are transferred from the semiconductor memory device200 to the semiconductor memory device controller 300, the edges of thedata windows are synchronized with the edge of the source clock ISCK.

The write command IWT and the read command IRD transferred from thesemiconductor memory device controller 300 to the semiconductor memorydevice 200 are included in the predetermined command IWCDR. Thepredetermined command IWCDR may include not only the write command IWTand the read command IRD, but also diverse operation mode commands for asemiconductor memory device. In particular, a predetermined commandIWCDR may include an auto-refresh operation mode entering command, whichis one of the operation modes that uses the most power in asemiconductor memory device, or conversely may include a stand-byoperation mode entering command, which is one of the operation modesthat uses the least power in a semiconductor memory device.

The reason why the predetermined command IWCDR can include the writecommand IWT, the read command IRD, and other diverse operation modecommands for a semiconductor memory device is that a command decoder 204is designed to toggle the predetermined command IWCDR when the writecommand IWT, the read command IRD, and other diverse operation modecommands for a semiconductor memory device are toggled in a case wherethe recovery information enable signal WCDR_ENABLE is enabled and thesemiconductor memory device enters the recovery information operationmode or the recovery information training operation mode.

For the second data input/output unit 220 and the recovery informationdata input/output unit 240 to operate, the recovery information enablesignal WCDR_ENABLE should be enabled. Herein, the enablement moment, thedisablement moment, and the length of the enabled duration of therecovery information enable signal WCDR_ENABLE are predetermined in thememory register set (MRS) 202 inside the semiconductor memory device200.

FIG. 10 is a timing diagram illustrating an operation of applying atraining input command to a semiconductor memory device in accordancewith an exemplary embodiment of the present invention.

Referring to FIG. 10, a ‘WCDR’ command is applied at a moment ‘T0,’ amoment ‘T2,’ a moment ‘T4,’ and a moment ‘T6’ of the source clock SCK orISCK in the semiconductor memory device according to an exemplaryembodiment of the present invention. Accordingly, it may be seen thatthe training input command IWRTR is toggled at a moment ‘T1,’ a moment‘T3,’ a moment ‘T5,’ and a moment ‘T7’ of the source clock SCK or ISCK.

The reason why the toggling moment of the training input command IWRTRis later than the moment when the ‘WCDR’ command is inputted is that thecommand decoder 204 needs operation time. Also, since the internalsource clock ISCK is generated by buffering an external source clockSCK, the internal source clock ISCK is toggled a little later than theexternal source clock SCK. However, since this does not change theoperation of the semiconductor memory device, the internal source clockISCK and the external source clock SCK will not be distinguished in thedescription of the present patent specification.

Since the write latency WL is assumed to be ‘3’ after the training inputcommand IWRTR is toggled, the recovery information training data WCDRTRAIN DATA, whose data window is scanned based on an edge of each sourceclock ISCK, is applied through the recovery information datainput/output pad 185 from the moment ‘T3,’ the moment ‘T5,’ the moment‘T7,’ and the moment ‘T9’ of the source clock SCK or ISCK correspondingto a determined first moment, as soon as the normal training data NORMALTRAIN DATA is applied through the normal data input/output pad 181.

To be specific, the normal input counter 1026 starts counting the numberof toggling times of the source clock ISCK, in response to a toggling ofthe training input command IWRTR as soon as the recovery informationinput counter 1221 starts counting the number of toggling times of thesource clock ISCK. Herein, since the write latency WL is assumed to be‘3,’ the recovery information input counter 1221 and the normal inputcounter 1026 count the number of times that the source clock ISCK istoggled three times from the moment ‘T1,’ the moment ‘T3,’ the moment‘T5,’ and the moment ‘T7,’ which are moments when the training inputcommand IWRTR is toggled, and toggle a recovery information input enablesignal WCDRINEN and a normal input enable signal WTEN at the moment‘T4,’ a moment ‘T6,’ a moment ‘T8,’ and a moment ‘T10’ of the sourceclock ISCK when the counting operation is ended.

As described above, the recovery information training data WCDR TRAINDATA applied through the recovery information data input/output pad 185is latched in parallel by delaying the recovery information input enablesignal WCDRINEN toggled at the moment ‘T4,’ a moment ‘T6,’ a moment‘T8,’ and a moment ‘T10’ of the source clock ISCK and toggling therecovery information input latch signal WCDR STROBE. Although notdirectly illustrated in the drawing, the normal training data NORMALTRAIN DATA, which is applied through the normal data input/output pad181, is latched in parallel by using a normal input latch signal NORMALSTROBE (not shown), which is obtained by delaying the normal inputenable signal WTEN by a certain time.

Herein, the latched normal training data NORMAL TRAIN DATA and recoveryinformation training data WCDR TRAIN DATA are inputted in series fromthe moment ‘T3,’ the moment ‘T5,’ the moment ‘T7,’ and the moment ‘T9’of the source clock ISCK and become data values completed withparallelization between the moment ‘T4’ and the moment ‘T5’, between themoment ‘T6’ and the moment ‘T7,’ between the moment ‘T8’ and the moment79/ and between the moment ‘T10’ and the moment ‘T11,’ respectively.

Herein, the time difference between the recovery information inputenable signal WCDRINEN and the recovery information input latch signalWCDR STROBE and the difference between the normal input enable signalWTEN and the normal input latch signal NORMAL STROBE (not shown) aretime asynchronized with the source clock ISCK, and they are values thatmay become different according to burst lengths BL of the normaltraining data NORMAL TRAIN DATA and the recovery information trainingdata WCDR TRAIN DATA.

Subsequently, the normal training data NORMAL TRAIN DATA and therecovery information training data WCDR TRAIN DATA, which are latchedbetween the moment ‘T4’ and the moment ‘T5,’ between the moment ‘T6’ andthe moment ‘T7,’ between the moment ‘T8’ and the moment ‘T9,’ andbetween the moment ‘T10’ and the moment ‘T11,’ are respectively storedin a predetermined space inside the normal training data input unit 1023and a recovery information data storage unit 1264 in parallel bysequentially toggling first internal input strobe signals WCDR PIN<0>,WCDR PIN<1>, WCDR PIN<2>, and WCDR PIN<3> from the moment ‘T5,’ themoment ‘T7,’ the moment ‘T9,’ and the moment ‘T11’ of the source clockISCK in response to a toggling of the recovery information input latchsignal WCDR STROBE and the normal input latch signal NORMAL STROBE (notshown).

The timing diagram illustrated in the drawing assumes a state wheresemiconductor memory device operates corresponding to the training inputcommand IWRTR. Thus, the first internal input strobe signal WCDRPIN<0:M> (where M=3 in the example shown in the drawing) is toggled inresponse to the toggling of the recovery information input latch signalWCDR STROBE, and if it operates corresponding to the predeterminedcommand IWCDR, a second internal input strobe signal WCDR PIN<0:N>(where N=3 in the example shown in the drawing) is toggled in responseto the toggling of the recovery information input latch signal WCDRSTROBE.

In short, even when the semiconductor memory device operatescorresponding to the predetermined command IWCDR, the recoveryinformation data WCDR DATA is inputted and stored through the sametiming diagram as illustrated in FIG. 10.

Also, when the semiconductor memory device operates according to thewrite command IWT (which may be included in the predetermined commandIWCDR), the normal data NORMAL DATA and the recovery information dataWCDR DATA may be inputted and stored through the same timing diagram asillustrated in FIG. 10.

As described above, when the normal training data NORMAL TRAIN DATA, therecovery information training data WCDR TRAIN DATA, the normal dataNORMAL DATA, and the recovery information data WCDR DATA are applied tothe semiconductor memory device, command signals, such as thepredetermined command IWCDR including the training input command IWRTRand the write command IWT, are applied at a moment when a time definedby a write latency WL passes from the moment that they are applied.

If there are any differences, the normal training data NORMAL TRAIN DATAand the recovery information training data WCDR TRAIN DATA are appliedin a state where their data windows are scanned based on an edge of thesource clock ISCK, and the normal data NORMAL DATA is applied insynchronization with the center of the source clock ISCK, while therecovery information data WCDR DATA is applied in synchronization withan edge of the source clock ISCK.

Herein, the method of applying a data by scanning a data window based onan edge of the source clock ISCK, which is the method of applying thenormal training data NORMAL TRAIN DATA and the recovery informationtraining data WCDR TRAIN DATA, is as described with reference to FIG.12.

In other words, among the range of a data window corresponding to aplurality of bits included in each of the normal training data NORMALTRAIN DATA and the recovery information training data WCDR TRAIN DATA, apoint corresponding to the edge of the source clock ISCK is sequentiallychanged at a certain interval from a starting point to an end point.

As described above, when the normal training data NORMAL TRAIN DATA andthe recovery information training data WCDR TRAIN DATA are stored in apredetermined space inside the semiconductor memory device and thevalues of the normal training data NORMAL TRAIN DATA and the recoveryinformation training data WCDR TRAIN DATA are detected in thesemiconductor memory device controller under the assumption that theedge of the source clock ISCK is the center of the data window, it ispossible to detect the exact location of the center corresponding to theedge of the source clock ISCK in the data windows of the normal trainingdata NORMAL TRAIN DATA and the recovery information training data WCDRTRAIN DATA transferred between the semiconductor memory device and thesemiconductor memory device controller based on the detection result.

FIG. 11 is a timing diagram illustrating an operation of applying atraining output command to a semiconductor memory device in accordancewith an exemplary embodiment of the present invention.

Referring to FIG. 11, in the semiconductor memory device according to anexemplary embodiment of the present invention, an ‘RDTR’ command isapplied at a moment ‘T0,’ a moment ‘T2,’ a moment ‘T4,’ and a moment‘T6’ of a source clock ISCK, and accordingly, a training output commandIRDTR is togged at a moment ‘T1,’ a moment ‘T3,’ a moment ‘T5,’ and amoment ‘T7’ of a source clock ISCK.

The reason why the toggling moment of the training input command IWRTRis later than the moment when the ‘RDTR’ command is inputted is that thecommand decoder 204 needs time to operate. Also, since the internalsource clock ISCK is generated by buffering an external source clockSCK, the internal source clock ISCK is toggled a little later than theexternal source clock SCK. However, since this does not change theoperation of the semiconductor memory device, the internal source clockand the external source clock will not be distinguished in thedescription of the present patent specification.

Since the column latency CL is assumed to be ‘5’ after the trainingoutput command IRDTR is toggled, the feedback recovery informationtraining data FB WCDR TRAIN DATA, whose data window is scanned based onan edge of each source clock ISCK, is outputted through the recoveryinformation data input/output pad 185 from the moment ‘T5,’ the moment‘T7,’ the moment ‘T9,’ and the moment ‘T11,’ of the source clock SCK orISCK corresponding to a determined second moment, as soon as thefeedback normal training data FB NORMAL TRAIN DATA is applied throughthe normal data input/output pad 181.

To be specific, the normal output counter 1021 starts counting thenumber of toggling times of the source clock ISCK in response to atoggling of the training output command IRDTR. Herein, since the columnlatency CL is assumed to be ‘5,’ the recovery information input counter1221 counts the number of times that the source clock ISCK is toggledone time from the moment ‘T1,’ the moment ‘T3,’ the moment ‘T5,’ and themoment ‘T7’ of the source clock ISCK, which are moments when thetraining output command IRDTR is toggled, and toggles a normal outputenable signal RDEN at a moment ‘T2,’ a moment ‘T4,’ a moment ‘T6,’ and amoment ‘T8’ of the source clock ISCK when the counting operation isended.

Herein, the reason why the normal output counter 1021 counts the numberof toggling times of the source clock ISCK only once, although thecolumn latency CL is ‘5,’ is that the column latency CL requires aminimum amount of time for receiving a command and actually outputting adata therein. In other words, it is assumed in the drawing that theminimum time required for internal preparation from the reception of acommand and the actual output of a data is a time corresponding to threeperiods of the source clock ISCK. Therefore, when the column latency CLis ‘5,’ the normal output counter 1021 needs a time corresponding to oneperiod of the source clock ISCK to wait while counting.

The first and second recovery information output enable signal togglingcontrollers 1224 toggle a recovery information output enable signalWCDROUTEN at a moment ‘T3,’ a moment ‘T5,’ a moment ‘T7,’ and a moment‘T9’ of the source clock ISCK in response to a normal output enablesignal RDEN toggled at a moment ‘T2,’ a moment ‘T4,’ a moment ‘T6,’ anda moment ‘T8’ of the source clock ISCK.

Likewise, the normal output strobe signal generator 1022 toggles (notdirectly illustrated in the drawing) a normal output strobe signal DOUTSTROBE at the moment ‘T3,’ the moment ‘T5,’ the moment ‘T7,’ and themoment ‘T9’ of the source clock ISCK in response to a normal outputenable signal RDEN toggled at a moment ‘T2,’ a moment ‘T4,’ a moment‘T6,’ and a moment ‘T8’ of the source clock ISCK.

As described above, the first internal output strobe signals WCDRPOUT<0>, WCDR POUT<1>, WCDR POUT<2>, and WCDR POUT<3> are sequentiallyenabled at the moment ‘T4,’ the moment ‘T6,’ the moment ‘T8,’ and themoment ‘T10’ of the source clock ISCK in response to the recoveryinformation output enable signal WCDROUTEN toggled at the moment ‘T3,’the moment ‘T5,’ the moment ‘T7,’ and the moment ‘T9’ of the sourceclock ISCK, and the recovery information training data WCDR TRAIN DATAis outputted in parallel to the recovery information data storage unit1264.

Likewise, normal data internal output strobe signals (not directlyillustrated in the drawing) are sequentially enabled at the moment ‘T4,’the moment ‘T6,’ the moment ‘T8,’ and the moment ‘T10’ of the sourceclock ISCK in response to the normal output strobe signal DOUT STROBEtoggled at the moment ‘T3,’ the moment ‘T5,’ the moment ‘T7,’ and themoment ‘T9’ of the source clock ISCK, and the normal training dataNORMAL TRAIN DATA stored in parallel in the predetermined space insidethe normal training data input unit 1023 is outputted in parallel.

The recovery information training data WCDR TRAIN DATA outputted inparallel is serialized through a recovery information serializing unit1252, and then a serialized feedback recovery information training dataFB WCDR TRAIN DATA is outputted through a recovery information datainput/output pad 185 in response to a recovery information output driverenable signal WCDR DOUT ENABLE.

Herein, the recovery information output driver enable signal WCDR DOUTENABLE is enabled in response to the recovery information output enablesignal WCDROUTEN toggled at the moment ‘T3,’ the moment ‘T5,’ the moment‘T7,’ and the moment ‘T9’ of the source clock ISCK, just like the firstinternal output strobe signals WCDR POUT<0>, WCDR POUT<1>, WCDR POUT<2>,and WCDR POUT<3>. The recovery information output driver enable signalWCDR DOUT ENABLE is always enabled in the durations where the firstinternal output strobe signals WCDR POUT<0>, WCDR POUT<1>, WCDR POUT<2>,and WCDR POUT<3> maintain the enabled state. Thus, the recoveryinformation output driver enable signal WCDR DOUT ENABLE continues to beenabled from the moment ‘T4’ of the source clock ISCK, which is a momentwhen the first internal output strobe signals WCDR POUT<0>, WCDRPOUT<1>, WCDR POUT<2>, and WCDR POUT<3> start to be enabled.

Since the timing diagram shown in the drawing assumes a state ofoperation corresponding to the training output command IRDTR, the firstinternal output strobe signals WCDR POUT<0:M> (where M=3 in the exampleshown in the drawing) are toggled in response to a toggling of therecovery information output enable signal WCDROUTEN. However, when in astate of operation corresponding to the predetermined command IWCDR, andnot the training output command IRDTR, the second internal output strobesignals WCDR POUT<0:N> (where N=3 in the example shown in the drawing)are toggled in response to a toggling of the recovery information outputenable signal WCDROUTEN.

Of course, when in a state of operation corresponding to thepredetermined command IWCDR, the feedback recovery information data FBWCDR DATA is outputted through a timing diagram different from that ofFIG. 11.

In other words, when the recovery information data WCDR DATA isinputted/outputted in a state of operation corresponding to thepredetermined command IWCDR, the recovery information data WCDR DATA isinputted, according to the timing diagram shown in FIG. 10, in responseto the training input command IWRTR, stored, and the stored recoveryinformation data WCDR DATA is outputted as the feedback recoveryinformation data FB WCDR DATA at a moment when the period of the sourceclock ISCK corresponding to the recovery information latency WCDRLpasses.

However, when semiconductor memory device is in a state of operationcorresponding to the read command IRD (included in the predeterminedcommand IWCDR), the normal data NORMAL DATA is outputted according tothe same timing diagram as illustrated in FIG. 11.

As described above, when the normal training data NORMAL TRAIN DATA, orthe recovery information training data WCDR TRAIN DATA, or the normaldata NORMAL DATA are outputted from the semiconductor memory device,command signals, which are the predetermined command IWCDR including thetraining input command IWRTR and the write command IWT, are outputted ata moment when a time defined by a column latency passes from a momentwhen the command signals are applied.

On the other hand, when the recovery information data WCDR DATA isoutputted from the semiconductor memory device, it is outputted at amoment when a time, defined by an internally determined recoveryinformation latency WCDRL, passes from a moment when the recoveryinformation data WCDR DATA is stored in the semiconductor memory device.

Also, when the normal training data NORMAL TRAIN DATA, or the recoveryinformation training data WCDR TRAIN DATA, the normal data NORMAL DATA,or the recovery information data WCDR DATA are outputted from thesemiconductor memory device, they are outputted in a state where theedges of their data windows are synchronized with an edge of the sourceclock ISCK.

According to one exemplary embodiment of the present invention, althoughthe phase of a normal data is changed due to a change in the operationtemperature or operation power of a semiconductor system, which includesa semiconductor memory device and a semiconductor memory devicecontroller, the normal data can be stably inputted/outputted at alltimes between the semiconductor memory device controller and thesemiconductor memory device by sensing the change in the phase based ona recovery information data, which is inputted/outputted between thesemiconductor memory device controller and the semiconductor memorydevice at the same timing that the normal data is inputted/outputted,and correcting the phase of the normal data based on the sensing result.

Also, the reliability of the recovery information data WCDR DATAtransferred between the semiconductor memory device controller and thesemiconductor memory device may be improved by training the phases of arecovery information training data WCDR TRAIN DATA and a source clockISCK so as to control the phase of the recovery information data WCDRDATA in a training operation performed in the initial state of anoperation of the semiconductor system, as well as training the phases ofthe normal training data NORMAL TRAIN DATA and the source clock ISCK soas to control the phase of the normal data NORMAL DATA.

When the operation temperature or operation power of the semiconductorsystem is altered, an operation for correcting the phase of the normaldata NORMAL DATA may be performed based on the recovery information dataWCDR DATA, and thus, the operation for correcting the phase of thenormal data can be performed with an improved reliability.

While the present invention has been described with respect to thespecific embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

For example, modifications to the location and kinds of the logic gatesand transistors exemplified in the above-described embodiment may berealized based on the polarity of an input signal.

1. A semiconductor memory device, comprising: a first data input/outputunit configured to receive a normal training data, whose data window isscanned based on an edge of a source clock, in response to a traininginput command, and output a data in a state where an edge of the datawindow is synchronized with the edge of the source clock in response toa training output command; and a second data input/output unitconfigured to receive a recovery information training data, whose datawindow is scanned based on the edge of the source clock, in response tothe training input command, and output a data in a state where an edgeof a data window is synchronized with the edge of the source clock inresponse to the training output command.
 2. The semiconductor memorydevice of claim 1, wherein the first data input/output unit receives anormal data in a state where a center of a data window is synchronizedwith the edge of the source clock in response to a write command, andoutputs a data in a state where an edge of the data window issynchronized with the edge of the source clock in response to a readcommand.
 3. The semiconductor memory device of claim 2, wherein thesecond data input/output unit receives a recovery information data whoseedge of a data window is synchronized with the edge of the source clockin response to a predetermined command, which is not the training inputcommand or the training output command, and outputs a data whose edge ofa data window is synchronized with the edge of the source clock after apredetermined time,
 4. The semiconductor memory device of claim 3,further comprising: a command input pad configured to receive thetraining output command and the predetermined command; a normal datainput/output pad configured to input/output the normal data and thenormal training data; and a recovery information data input/output padconfigured to input/output the recovery information data and therecovery information training data.
 5. The semiconductor memory deviceof claim 4, wherein the read command and the write command are includedin the predetermined command.
 6. The semiconductor memory device ofclaim 5, wherein the second data input/output unit comprises: a recoveryinformation input/output controller configured to generate a firstinternal input strobe signal at a timing corresponding to an internalinput moment of the recovery information training data in response tothe training input command, and generate a first internal output strobesignal at a timing corresponding to an internal output moment of therecovery information training data in response to the training outputcommand; recovery information data input/output units configured toinput/output recovery information training data through the recoveryinformation data input/output pad; and a recovery information storageconfigured to store the recovery information training data for a certaintime in response to the first internal input strobe signal and the firstinternal output strobe signal.
 7. The semiconductor memory device ofclaim 6, wherein the recovery information input/output controllergenerates a second internal input strobe signal at a timingcorresponding to an internal input moment of the recovery informationdata and generates a second internal output strobe signal at a timingcorresponding to an internal output moment of the recovery informationdata in response to the predetermined command.
 8. The semiconductormemory device of claim 7, wherein the recovery information datainput/output units input/output recovery information data through therecovery information data input/output pad, and the recovery informationstorage stores the recovery information data for a predetermined time inresponse to the second internal input strobe signal and the secondinternal output strobe signal.
 9. The semiconductor memory device ofclaim 8, wherein the recovery information input/output controllercomprises: a recovery information input control block configured totoggle the first internal input strobe signal or the second internalinput strobe signal at a moment after a time period, during which theperiod of the source clock is repeated a first number of times, elapsesfrom a moment when the training input command or the predeterminedcommand is inputted; and a recovery information output control blockconfigured to toggle the first internal output strobe signal at a momentafter a time period, during which the period of the source clock isrepeated a second number of times, elapses from a moment when thetraining output command is inputted, and toggle the second internaloutput strobe signal at a moment after a time period, during which theperiod of the source clock is repeated a third number of times, elapsesfrom a moment when the second internal input strobe signal is toggled.10. The semiconductor memory device of claim 9, wherein the recoveryinformation input control block comprises: a recovery information inputcounter configured to count the period of the source clock as many asthe first number of times from a moment when the training input commandor the predetermined command is inputted, and toggle a recoveryinformation input enable signal in response to a completion of thecounting; and an input strobe signal generation portion configured togenerate the first internal input strobe signal in response to thetoggling of the recovery information input enable signal when thetraining input command is inputted into the command input pad, andgenerate the second internal input strobe signal in response to therecovery information input enable signal when the predetermined commandis inputted into the command input pad.
 11. The semiconductor memorydevice of claim 10, wherein the recovery information output controlblock comprises: a first recovery information output enable signaltoggling controller configured to toggle a recovery information outputenable signal in response to a normal output enable signal which istoggled at a moment after a time period, during which the period of thesource clock is counted the second number of times, elapses from aninput moment when the training output command is inputted into thecommand input pad; a second recovery information output enable signaltoggling controller configured to count a number of times the period ofthe source clock repeats until the counted number equals the thirdnumber of times in response to a toggling of the recovery informationinput enable signal when the predetermined command is inputted into thecommand input pad, and toggle the recovery information output enablesignal in response to a completion of the counting; and an output strobesignal generation portion configured to generate the first internaloutput strobe signal in response to a toggling of the recoveryinformation output enable signal, when the training output command isinputted into the command input pad, and generate the second internaloutput strobe signal in response to a toggling of the recoveryinformation output enable signal, when the predetermined command isinputted into the command input pad.
 12. The semiconductor memory deviceof claim 11, wherein the input strobe signal generation portion: togglesa recovery information input latch signal with a predetermined timedifference in response to a toggling of the recovery information inputenable signal, toggles the first internal input strobe signal inresponse to a toggling of the recovery information input latch signalwhen the training input command is inputted, and toggles the secondinternal input strobe signal in response to a toggling of the recoveryinformation input latch signal when the predetermined command isinputted.
 13. The semiconductor memory device of claim 12, wherein theoutput strobe signal generation portion: consecutively toggles arecovery information output driver enable signal as many times as anumber corresponding to a bit number of the recovery information data orthe recovery information training data in response to a toggling of therecovery information output enable signal, toggles the first internaloutput strobe signal in response to a toggling of the recoveryinformation output enable signal when the training output command isinputted, and toggles the second internal output strobe signal inresponse to a toggling of the recovery information output enable signalwhen the predetermined command is inputted.
 14. The semiconductor memorydevice of claim 13, wherein the recovery information data input/outputunits comprise: a recovery information data input unit configured tobuffer the recovery information data or the recovery informationtraining data, which include a plurality of bits that are seriallyapplied through the recovery information data input/output pad, and tosynchronize the buffered data with the source clock for parallelization;and a recovery information data output unit configured to synchronizethe recovery information data or the recovery information training data,provided in a parallelized state through the recovery informationstorage, with the source clock so as to generate a serialized signal,and to output the serialized signal through the recovery informationdata input/output pad in response to a toggling of the recoveryinformation output driver enable signal.
 15. The semiconductor memorydevice of claim 14, wherein the recovery information storage comprises:a recovery information latch unit configured to latch the recoveryinformation data or the recovery information training data, which isparallelized through the recovery information data input unit, inparallel in response to a toggling of the recovery information inputlatch signal; a recovery information data storage unit configured tostore a data obtained from the parallel latching through the recoveryinformation latch unit in response to the first internal input strobesignal or the second internal input strobe signal, and provide thestored data to the recovery information data output unit in response tothe first internal output strobe signal or the second internal outputstrobe signal.
 16. The semiconductor memory device of claim 11, whereinwhen the training input command or the predetermined command isconsecutively inputted and the recovery information input enable signalis consecutively toggled, the input strobe signal generation portionconsecutively toggles the recovery information input latch signal inresponse to the consecutive toggling of the recovery information inputenable signal with a predetermined time difference; when the traininginput command is inputted consecutively, the input strobe signalgeneration portion sequentially toggles a plurality of signals includedin the first internal input strobe signal in response to the consecutivetoggling of the recovery information input latch signal; and when thepredetermined command is inputted consecutively, the input strobe signalgeneration portion sequentially toggles a plurality of signals includedin the second internal input strobe signal in response to theconsecutive toggling of the recovery information input latch signal. 17.The semiconductor memory device of claim 16, wherein when the trainingoutput command or the predetermined command are consecutively inputtedand the recovery information output enable signal is consecutivelytoggled, the output strobe signal generation portion consecutivelytoggles the recovery information output driver enable signal as manytimes as a number corresponding to a bit number of the recoveryinformation data or the recovery information training data in responseto the consecutive toggling of the recovery information output enablesignal; when the training output command is consecutively inputted, theoutput strobe signal generation portion sequentially toggles a pluralityof signals included in the first internal output strobe signal inresponse to the consecutive toggling of the recovery information outputenable signal; and when the predetermined command is consecutivelyinputted, the output strobe signal generation portion sequentiallytoggles a plurality of signals included in the second internal outputstrobe signal in response to the consecutive toggling of the recoveryinformation output enable signal.
 18. The semiconductor memory device ofclaim 13, wherein the recovery information data input/output unitscomprise: a recovery information data input unit configured tosequentially buffer a plurality of the recovery information data or aplurality of the recovery information training data, which each includea plurality of bits that are serially applied through the recoveryinformation data input/output pad, and to synchronize the buffered datawith the source clock for parallelization; and a recovery informationdata output unit configured to synchronize the plurality of the recoveryinformation data or the plurality of the recovery information trainingdata, provided in a parallelized state through the recovery informationstorage, with the source clock for serialization, and to output aserialized signal through the recovery information data input/output padin response to a toggling of the recovery information output driverenable signal.
 19. The semiconductor memory device of claim 18, whereinthe recovery information storage comprises: a recovery information latchunit configured to sequentially latch the plurality of the recoveryinformation data or the plurality of the recovery information trainingdata, which are sequentially parallelized through the recoveryinformation data input unit, in parallel in response to consecutivetoggling of the recovery information input latch signal; and a recoveryinformation data storage unit configured to sequentially store datasequentially outputted from the parallel latching through the recoveryinformation latch unit in response to consecutive toggling of aplurality of signals included in the first internal input strobe signalor the second internal input strobe signal, and to sequentially providethe stored data to the recovery information data output unit in responseto sequential toggling of the plurality of signals included in the firstinternal output strobe signal or the second internal output strobesignal.
 20. The semiconductor memory device of claim 11, wherein thefirst data input/output unit comprises: a normal input control blockconfigured to receive and store the normal training data at a momentafter a time period, during which the period of the source clock isrepeated the first number of times, elapses from a moment when thetraining input command is inputted; and a normal output control blockconfigured to output the normal training data stored through the normalinput control block at a moment after a time period, during which theperiod of the source clock is repeated the second number of times,elapses from a moment when the training output command is inputted. 21.The semiconductor memory device of claim 20, wherein the normal inputcontrol block comprises: a normal input counter configured to count theperiod of the source clock as many as the first number of times from amoment when the training input command is inputted, and toggle a normalinput enable signal in response to the completion of the counting; anormal input strobe signal generator configured to generate a normalinput strobe signal in response to a toggling of the normal input enablesignal; and a normal training data input unit configured to receive thenormal training data through the normal data input/output pad and storethe normal training data in a predetermined register in response to thenormal input strobe signal.
 22. The semiconductor memory device of claim21, wherein the normal output control block comprises: a normal outputcounter configured to count the period of the source clock as many asthe second number of times from a moment when the training input commandis inputted, and toggle the normal output enable signal in response to acompletion of the counting; a normal output strobe signal generatorconfigured to generate a normal output strobe signal in response to atoggling of the normal output enable signal; and a normal training dataoutput unit configured to output the normal training data stored in thepredetermined register through the normal data input/output pad inresponse to the normal output strobe signal.
 23. The semiconductormemory device of claim 5, wherein a time elapsing from a moment when thetraining input command is inputted into the command input pad to amoment when the normal training data is inputted into the normal datainput/output pad is the same as a time elapsing from a moment when thetraining input command is inputted into the command input pad to amoment when the recovery information training data is inputted into therecovery information data input/output pad.
 24. The semiconductor memorydevice of claim 23, wherein a time elapsing from a moment when thetraining output command is inputted into the command input pad to amoment when the normal training data is outputted through the normaldata input/output pad is the same as a time elapsing from a moment whenthe training output command is inputted into the command input pad to amoment when the recovery information training data is outputted throughthe recovery information data input/output pad.
 25. The semiconductormemory device of claim 24, wherein a time elapsing from a moment whenthe write command is inputted into the command input pad to a momentwhen a normal data is inputted into the normal data input/output pad; atime elapsing from a moment when the predetermined command is inputtedinto the command input pad to a moment when the recovery informationdata is inputted into the recovery information data input/output pad; atime elapsing from a moment when the training input command is inputtedinto the command input pad to a moment when the normal training data isinputted into the normal data input/output pad; and a time elapsing froma moment when the training input command is inputted into the commandinput pad to a moment when the recovery information training data isinputted into the recovery information data input/output pad are thesame.
 26. The semiconductor memory device of claim 25, wherein a timeelapsing from a moment when the read command is inputted into thecommand input pad to a moment when the normal data is outputted throughthe normal data input/output pad and a time elapsing from a moment whenthe training output command is inputted into the command input pad to amoment when the normal training data and the recovery informationtraining data are outputted through the normal data input/output pad arethe same, but different from a time elapsing from a moment when thepredetermined command is inputted into the command input pad to a momentwhen the recovery information data is outputted through the recoveryinformation data input/output pad.
 27. The semiconductor memory deviceof claim 8, wherein the source clock comprises: a system clock forsynchronizing the training input command, the training output command,and the predetermined command that are inputted through the commandinput pad; and a data clock for synchronizing the normal data, thenormal training data, the recovery information, and the recoveryinformation training data that are inputted/outputted through the normaldata input/output pad and the recovery information data input/outputpad.
 28. The semiconductor memory device of claim 27, wherein therecovery information input/output controller comprises: a recoveryinformation input control block configured to toggle the first internalinput strobe signal and the second internal input strobe signal at amoment after a time period, during which the period of the system clockis repeated the first number of times, elapses from a moment when thetraining input command or the predetermined command is inputted; and arecovery information output control block configured to toggle the firstinternal output strobe signal at a moment after a time period, duringwhich the period of the source clock is repeated the second number oftimes, elapses from a moment when the training output command isinputted, and to toggle the second internal output strobe signal at amoment after a time period, during which the period of the source clockis repeated the third number of times, elapses from a moment when thefirst and second internal input strobe signals are toggled.
 29. A methodfor operating a semiconductor memory device, comprising: applying atraining input command; applying a normal training data and a recoveryinformation training data at a first moment, after the applying of thetraining input command, by scanning each data window based on an edge ofa source clock; applying a training output command; outputting thereceived normal training data and the received recovery informationtraining data at a second moment in a state where an edge of a datawindow is synchronized with the edge of the source clock, after theapplying of the training output command.
 30. The method of claim 29,further comprising: applying a write command; applying a read command;applying a first normal data at the first moment after the applying ofthe write command in a state where a center of a data window issynchronized with the edge of the source clock; and outputting a secondnormal data stored inside at the second moment after the applying of theread command in a state where an edge of a data window is synchronizedwith the edge of the source clock.
 31. The method of claim 30, furthercomprising: applying a predetermined command; and receiving a recoveryinformation data in a state where an edge of a data window issynchronized with the edge of the source clock at the first moment,after the applying of the write command, the read command, and thepredetermined command, and outputting the applied data in a state whereedges of data windows are synchronized with the edge of the source clockafter a predetermined time.
 32. The method of claim 31, wherein thepredetermined command comprises the read command and the write command.33. The method of claim 32, wherein the applying of the training datacomprises: counting a period of the source clock a first number oftimes, after the applying of the training input command; and receivingand storing the normal training data and the recovery informationtraining data in response to a completion of the counting of the periodof the source clock the first number of times.
 34. The method of claim33, wherein the outputting of the training data comprises: counting theperiod of the source clock a second number of times, after the applyingof the training output command; and outputting the normal training dataand the recovery information training data, which are stored through thereceiving and storing the normal training data and the recoveryinformation training data, in response to a completion of the countingof the period of the source clock the second number of times in a statewhere edges of data windows are synchronized with the edge of the sourceclock.
 35. The method of claim 34, wherein the receiving the recoveryinformation data in the state that the edge of the data window issynchronized with the edge of the source clock at the predeterminedfirst moment after the applying of the write command, the read commandand the predetermined command, and the outputting the applied data inthe state that edges of data windows are synchronized with the edge ofthe source clock after the predetermined time comprises: counting theperiod of the source clock in the predetermined first number of timesafter the applying of the write command, the read command and thepredetermined command; receiving and storing the recovery informationdata in response to a completion of the counting the period of thesource clock in the predetermined first number of times after theapplying of the write command, the read command and the predeterminedcommand; counting the period of the source clock in a predeterminedthird number of times in response to a completion of the receiving andstoring the recovery information data in response to the completion ofthe counting the period of the source clock in the predetermined firstnumber of times after the applying of the write command, the readcommand and the predetermined command; and outputting the recoveryinformation data, which is stored through the receiving and storing therecovery information data in response to a completion of the countingthe period of the source clock in the predetermined first number oftimes after the applying of the write command, the read command and thepredetermined command, in response to a completion of the counting theperiod of the source clock in the predetermined third number of times inresponse to the completion of the receiving and storing the recoveryinformation data in response to the completion of the counting theperiod of the source clock in the predetermined first number of timesafter the applying of the write command, the read command and thepredetermined command in a state that the edge of the data window issynchronized with the edge of the source clock.
 36. The method of claim32, further comprising: receiving the training input command, thetraining output command, and the predetermined command through a commandinput pad; inputting/outputting the first normal data, the second normaldata, and the normal training data through a normal data input/outputpad; inputting/outputting the recovery information data and the recoveryinformation training data through a recovery information datainput/output pad; and inputting the source clock through a clock inputpad.